During the story, characters may ask a question to the main character about his feelings/thoughts on things. These may not affect the story much no matter what you choose, though I will include the responses I gave just to be safe. Still, feel free to respond with your own thoughts when asked.

Additionally, I'll be calling out the location of lost spirits (used to upgrade items when you reach a certain part in the story) that can modify success chances. TYPICALLY it doesn't matter who takes an action, so if you have a different partner/success chance than I did from buying the upgrades, you should go with whatever option has the highest success rate. The options I use are confirmed to work if they succeed, so take note if I call out who performs the action or if you should team up.

For veterans of the original Death Mark - unlike the first game, every scenario is passable with any companion, but success chances may vary. You will need to swap partners to access some Lost Souls, so if you can't get one I call out in the guide, try switching partners. I do make a note of when I suggest switching partners, so if you follow those call-outs, you will be fine.

-Enter Room 1-B
-Speak to the girl inside. Chat, then ask about all topics.
-Continue to the right and enter the women's bathroom.
-Enter the final stall on the left.
-Pick up the marker on the ground and examine the writing on the wall.
-Go all the way to the right and enter the music room.
-Examine the piano, and choose to flick the keys.
-Go left and examine the flyer that dropped to the ground.
-Leave the music room and run all the way to the left to enter the infirmary.
-Talk to Konoe about everything.
-Return to the area just to the right of the music room and travel to the connecting corridor.
-Proceed right, and when you find Izumi, ask him about The Departed.
-Continue right into the old school building, then enter the music room on the right.

SUSPENSIVE ACT
Choose to have the main character execute the command, and choose Konoe's Knife.
SURVIVED!

-Travel to the left down the corridor and enter the women's restroom.
-Enter the middle stall and pick up the handkerchief on the ground.
-Enter the left stall and examine the blood.
-Leave the restroom and go all the way left in the hallway.
-After the scene, return to the old building.
-Go left and enter the female restroom again.
-Enter the left stall.

SUSPENSIVE ACT
Choose to use the dirty handkerchief and wipe away the graffiti.
Choose the red marker and write "Hanako Akai".
SURVIVED!

-Return to the Infirmary.
-Choose to reassure Himeko.
-Follow the hallway to the right.
-Choose to go to the corridor.

-Add at least five cubes of sugar to your coffee, if you want to drink some.
-Go to the faculty room when prompted.
-Ask Konoe about all options.
-Say you don't have much of a choice.
-Return to the infirmary.
-Ask Ai about all options.
-Head to the student council room.
-Tell Himeko you're a teacher.
-Chat and ask about all topics.
-Head to the new building's music room and talk to Michiho.
-Chat and ask about all topics.
-Go to the third floor, classroom 3-C and talk to the boys inside.
-Go to the first floor, classroom 3-B and talk to the group of three girls inside.
-Examine the main entrance/shoe locker area on the first floor.
-Choose to eavesdrop

SUSPENSIVE ACT
Have Ai approach the girls naturally.
Have Ai pretend to wait for a friend.
SURVIVED!

-Go to the second floor, classroom 2-B.
-Talk to the girl inside. Chat and ask about all options.
-Try to stop her
-Leave the classroom and return to the infirmary.
-Ask Diamon about all options, then take Ai with you.
-Head to the student council room.
-Choose to compliment Michiho on her hair color.
-Chat and ask about all options.
-Say you consider Ai a friend.
-Switch partners to Daimon and go to the faculty room.
-Ask Daimon to step in.
-Chat and ask about all options.
-Switch back to Ai.
-Go to the new school building's first floor, go all the way to the right and talk to Himeko.
-Go into the music room, then head to the right again to enter the storage room.

SUSPENSIVE ACT
Have Ai ask her if she lost something.
Have Ai state that the handkerchief was embroidered with N.H.
SURVIVED!

-Chat and ask about all options.
-Examine the glass case on the right side of the storage room.
-Return to the infirmary.
-Select "To Meet Hanako".

-Choose Daimon as your ally.
-Head to the connecting corridor.
-Say you're scared.
-Continue to the old school building.
-Enter the first floor's women's restroom and open the middle stall.
-Examine the broken broom on the floor.
-Examine the shoe locker area and open the locker for LOST SOUL 1.
-Enter classroom 1-B and check the locker on the left side of the room for rubber gloves.
-Enter classroom 1-C and check the rightmost stack of desks for LOST SOUL 2.
-Enter the men's restroom and check the toilet in the rightmost stall. Use rubber gloves to retrieve LOST SOUL 3.
-Go to the second floor and enter the men's restroom.
-Examine the urinals for LOST SOUL 4.
-Examine the cleaning cabinet to the left of the stalls for a plunger.
-Enter the second floor's women's restroom and examine the mirror. Reach for the item for LOST SOUL 5.
-Examine the toilet in the left stall and use the plunger.
-Head left to classroom 2-B and examine the water on the floor.
-Go to the third floor and enter the women's restroom. Examine the toilet in the first stall and use rubber gloves for LOST SOUL 6.
-Head to the third floor, classroom 3-B. Examine the cupboard on the left for LOST SOUL 7.
-Enter classroom 3-C and examine the boombox on the desk.
-Return to the first floor and enter the music room.
-Examine the figure sitting at the piano.
-Go to the third floor women's restroom and enter the left stall.

SUSPENSIVE ACT
Have Daimon use the plunger to PULL the door open.
SURVIVED!

-Go back to the third floor women's restroom and enter the left stall.
-Pick up the key on the ground.
-Change partners to Ai.
-Go to the first floor's music room and unlock the storage room on the right.
-Examine the large shelf for LOST SOUL 8.
-Examine the tuba to find a diary.
-Examine the diary in your inventory and enter 526.
-Read all the entries.
-Return to the old music room's storage room and check the boxes on the left.
-When ready, take the uniform and step outside the storage room.

SUSPENSIVE ACT
Team up to throw Hanako's uniform at her.
Team up and shove the broken mop at Hanako's face.
Team up and sing the song.
SURVIVED!

-Return to the third floor women's restroom and open the left stall.
-Return to the infirmary and talk to the others.
-Say you should use sacred objects.
-Go to the old building's first floor women's restroom.
-Go to the old building's music room's storage room.
-Say you're the one being chased.

-Ask "What about your job?"
-Head to the Faculty room.
-Say "I'm not cut out for this."
-Teach "The horrors of the H City Air Raid"
-Head to the Faculty room.
-Ask Shou all questions
-Go to the student council room.
-Examine the left cabinet, the papers on the whiteboard, the notebook on the desk, and the trash can.
-Chat and discuss all topics with Himeko.
-Return to the Infirmary.
-Head to the new school building and leave through the main entrance by the shoe lockers.
-Check the ground just to the right of the main entrance for LOST SOUL 1.
-Speak to Michiho to the left of the gate.
-Tell her she can join for a while.
-Say "Let's do our best, Michiho."
-Chat and discuss all topics.
-Head left to the bus stop and talk to the boy there.
-Examine the sign on the right.
-Say "After you get off the bus"
-Get off at M Town Shop
-Examine the sign on the shop's window for LOST SOUL 2.
-Examine the bus stop sign, take the bus bound for M Tower, and get off at S Cemetery.
-Examine the scissors on the road, just to the left of Shou.
-Examine the gate to the far left for LOST SOUL 3.
-Enter the door to the cemetery.
-Examine the grave just to the right of the middle of the screen. You will be able to inspect it, then choose to Arrange it to clean it up. Do so for LOST SOUL 4.
-Examine the boxes on the rightmost grave, then choose to open them.

SUSPENSIVE ACT
Have Shou interact with the small box and choose to return scissors to the grave.
SURVIVED!

-Enter the school and make your way back to the infirmary.
-Talk to Eita. Chat and ask about all topics.
-Go to the faculty room.
-Say "I know that".
-Chat and ask about all topics.
-Move to the library.
-Examine the bookcase on the left, behind the desk. Read both articles.
-Return to the faculty room and ask Ritsu about the victims from five years ago.
-Go to the new school building's second floor and enter the Art Room on the right.
-Pass through the Art Room and enter the storage room on the right.
-Examine the cupboard on the right.
-Move to the second floor of the old school building and enter the Art Room on the right.
-Examine the shelf on the left side of the room for a sketch pad.
-Examine the crack in the wall to the right of the easel for LOST SOUL 5.
-Enter the art storage room on the right.
-Say "Kashima!"
-Ask Michiho all questions.
-Change your partner to Daimon.
-Return to the old building's art storage room.
-Examine the broken statue for LOST SOUL 6.
-Examine the items on the shelf on the left, and use the blue pencil to get LOST SOUL 7.
-Examine the cupboard on the right for a notebook.
-Go to the library and examine the bookshelf in the back of the room for a book.
-Enter the gymnasium.
-Quickly move to the right and check in front of the second basketball hoop (to the right of the basket of basketballs) to destroy the curse.
-Move to the gymnasium storage through the door on the right.
-Examine the improperly folded mat on the right side of the room for LOST SOUL 8.
-Examine the stains on the wall, then touch them.

SUSPENSIVE ACT
Have Daimon use Newspaper Article B to say she was killed by Kashima.
Have Daimon use the Yearbook to say her name is Miho Shinji.
SURVIVED!

-Return to the infirmary and talk to the others.
-Choose "S.H.'s notebook and the pencil case".
-Choose "Kashima's words".
-Go to the faculty room and ask all questions.
-When ready, leave the school through the main entrance.
-Enter the hospital.
-Examine the curtain twice.
-Outside of the hospital, talk to the boy by the bus stop.
-Say "The one who borrowed the yearbook"
-Examine the bus sign to take the bus back to school.
-Choose "Escape into the school".
-Choose "Hirose Sousuke".
-Choose "Pretend to be Hirose".
-Choose "The old building's art room".
-Make your way to the old building's art room on the second floor.
-Examine the easel.

SUSPENSIVE ACT
Team up and have Daimon cut the MC's hair.
Use the brown pencil to draw a bellflower.
Team up to remove and return the black scissors in Kashima's mouth.
SURVIVED!

-Leave the school through the front gate.
-Take the bus to the cemetery.
-Examine the boxes in front of Kashima's grave.
-Take the bus back to the academy.
-Return to the infirmary and talk to Moe.
-Move to the old building.
-Choose "No".
-Say "Got it".
-Move left down the hallway and enter the empty classroom at the end.
-Say "It's too late to back out now".

-Say "Of course not."
-Move to the faculty room.
-Say "I am."
-Move to the student council room.
-Say "Only until a new notice arrives."
-Ask about all topics.
-Go to the library.
-Go to the infirmary.
-Move to the pool.
-Examine the left diving board for LOST SOUL 1.
-Examine the pool.

SUSPENSIVE ACT
Use the bucket to scoop up pool water.
Use the bucket to scoop up deeper water.
SURVIVED!

-Return to the infirmary.
-Talk to use the phone, and "Bring up Mr. Konoe".
-Move to the new school building.
-Examine the notice board to the left of the main entrance for LOST SOUL 2.
-Move to the connecting corridor.
-Look on the ground to the right of the opening in the pathway for LOST SOUL 3.
-From the middle of the path, move down to the courtyard.
-Examine the fox statue for LOST SOUL 4.
-Return to the connecting corridor and move up the middle path to the clock tower front.
-Move up to the clock tower.
-Help Douryou.
-Ask about all topics.
-Pick any option regarding the Departed's identity.
-Leave the infirmary, then pick all topics.
-Say "Don't think so".
-Say "I'd still believe you".

-Say "Of course."
-Ask about all topics.
-Choose "Ask her to at least cooperate".
-Go to the student council room.
-Go to the second floor of the new building and talk to Michiho by the staircase.
-Go to the third floor and almost all the way to the left, then talk to the boy in front of the empty classroom.
-Go back to the second floor and talk to Michiho.
-Say "I do not".
-Chat and ask about all topics.
-Say "The delinquent student".
-Go to room 2-C and talk to Kakuta about all topics.
-Go to the student council room and talk about all topics.
-Go to the second floor, move to the right and enter the second floor connecting corridor.
-Give the girl by the shrine a friendly greeting.
-Examine the shrine, then open it.

SUSPENSIVE ACT
Team up with Hiroo and use the bag to take the attack.
SURVIVED!

-Ask about all topics
-Go to the student council room and ask about the delinquent girl and creepy Petri dish.
-Go to the second floor and ask Michiho about the delinquent girl and creepy Petri dish.
-Go to room 2-C and ask Kakura about the delinquent girl and creepy Petri dish.
-Say "What he said about the mushrooms".
-Talk to Michiho on the second floor and choose chat.
-Go to the third floor and walk right to enter the science room.
-Continue right to enter the storage room.
-Say "The delinquent and the key".
-Examine the bear for LOST SOUL 1.
-Examine the documents on the floor.
-Go to the library.
-Chat, then agree to take the trial.

SUSPENSIVE ACT
Team up with Hiroo and show the Petri dish.
SURVIVED!

-Ask about all topics.
-Say "can't say either way".
-Return to the second floor connecting corridor.
-Examine the shrine again for LOST SOUL 2.
-Head to the infirmary.
-Ask about all topics.

-Use the Talk option and call Eita, ask about all topics.
-Switch to Mashita.
-Move to the connecting corridor, then the front of the clock tower, then move down to the shrine front gate.
-Enter the Fox Forest.
-Move to the right down the path.
-Examine a tree with mushrooms on it for LOST SOUL 3.
-Keep going and examine the sixth lantern on the path (marked by a snake) to reveal a path.
-Go down the snake path and examine the rock at the end.
-Touch it twice for LOST SOUL 4.
-Return to the main path, continue, and examine the tenth lantern (marked by a rooster) to find another path.
-Go down the rooster path.
-Examine the trashed sign on the left.
-Choose Clapping.
-Examine the drum on the right, then inspect it closer for LOST SOUL 5.
-Return to the main path.
-Go to the ninth lantern (monkey) and clap twice.
-Go to the third lantern (tiger) and clap three times.
-Go to the sixth lantern (snake) and clap once.
-Go all the way to the right and examine the figure.
-Examine the lantern behind him (boar) to reveal another path. Take it.
-Examine the stump on the left for a shovel.
-Examine the mass on the ground (slightly to the right of the stump) and use the shovel for LOST SOUL 6.
-Examine the fence on the left.
-Examine all areas.
-Say "Kakuta".
-Return to the main path, and follow it all the way to the right to enter the shrine.
-Examine the left lantern for LOST SOUL 7.
-Examine the forest in the back right.
-Use the shovel.

SUSPENSIVE ACT
Have the main character eat some of the mushrooms from the Petri dish.
Team up and use the gun in the paper bag to attack Kokkuri.
Team up and shoot Kokkuri's gun.
SURVIVED!

-Return to the infirmary and talk to the others.
-Call Eita.
-Say "The voice from the corpse".
-Go to the third floor of the old school building and enter the old science room on the right.
-Go to the right side of the room and examine the sink.
-Look on the ground to the left of the sink to destroy the curse.
-Examine the shelf to find a key.
-Move right to enter the storage room.
-Examine the cabinet on the right and use the small key to get a scalpel.
-Examine the boxes on the left side of the room for LOST SOUL 8.
-Examine the bottles on the left shelf.
-Switch to Hiroo to maximize your upcoming chances.
-Examine the stuffed fox and use the scalpel.
-Leave the science room.

SUSPENSIVE ACT
Have Hiroo use the Fox laccata document and say "Masaki Kiyohara".
Have Hiroo choose the Petri dish and say "Student K".
SURVIVED!

-Move to the connecting corridor, then return back to the Fox Forest.
-Go all the way to the right and enter the shrine.
-Return all the way to the special building and go to the faculty room.
-Examine the laptop on the right row of desks.
-Return to the infirmary and talk to the others.
-Say "I do".
-Leave the infirmary.
-Choose "Give it back".
-Say "The message itself".
-Say "But still..."

-Talk in the infirmary for a message from Shou.
-Move to the faculty room.
-Apologize
-Move to the student council room.
-Say "Thank you for your help."
-Enter the library
-Enter the faculty room
-Say "The Douryou and Kinukawa thing?"
-Go to the infirmary and talk to Abe.
-Move to the front gate of the school.
-Say "Slit-Mouthed Kashima"
-Say "Bus route map".
-Examine the mailbox on the wall.
-Examine the front door of the shop.
-Examine the door again and knock three times.
-Examine the mailbox again.
-Exit right back to the academy.
-Say "Six".
-Say "Toshihiko Izumi".
-Say "Don't tease your teacher."
-Examine the noticeboard to the left of the main entrance.
-Say "I'm glad." to receive LOST SOUL 1.
-Move to the library.
-Examine the bookcase on the right for LOST SOUL 2.
-Examine the cabinet behind the desk.
-Say "The clock tower."
-Go to the courtyard and examine the fox statue.
-Say "Let's give it a shot" for LOST SOUL 3.
-Go inside the clock tower.
-Examine the cabinet.
-Use the ladder to go to the second floor.
-Use the ladder to go to the third floor.
-Open the box and take the crowbar and wrench.
-Go back down to 2F and examine the middle of the floor.
-Use the wrench to get LOST SOUL 4.
-Go back to 1F and use the crowbar on the cabinet.

SUSPENSIVE ACT
Threaten to throw the wrench at The Departed
Take a defensive stance with the crowbar
SURVIVED!

-Tell her the situation
-Choose all options
-Nod

-Eat it
-Head to the faculty room
-Say "Don't know".
-Remain silent
-Go to the infirmary
-Go to the connecting hallway, then move to the courtyard.
-Check the ground in front of the fox statue for LOST SOUL 1.
-Go to the clock tower.
-Say "Vaguely".
-Examine the cabinet for LOST SOUL 2.
-Go to the third floor of the clock tower and examine the box for LOST SOUL 3.
-Return to the infirmary.
-Stop Douryou
-Say "No".
-Leave through the front gate of the school and head left to the bus stop.
-Examine the bench for LOST SOUL 4.
-Continue to the left to enter the dormitories.
-Examine the office window.
-Examine the elevator.
-Examine the fish tank on the shelf to get a dead frog.
-Examine the drawers to find LOST SOUL 5.
-Examine the other items in the room - the calendar, the desk, the bed, the fridge, the poster, and the notes on the wall.
-Say "There's no sign of life in this room."
-Say "The resident's preferences changed."
-Say "That's right".
-Return to the infirmary.
-Say "No"
-Go to the connecting corridor then move to the courtyard.
-Inspect the fox statue, then read the writing.
-Go back to the infirmary and talk to Himeko.
-Go to the student council room and examine the cabinets on the left.
-Return to the fox statue and use the bleach on it.
-Read the inscription.
-Go to the shrine entrance and enter Fox Forest.

SUSPENSIVE ACT
Have the main character read Sakamoto's report out loud.
SURVIVED!

-Ask where the main shrine is.
-Continue down the path to the right.
-Examine the fourth lantern (rabbit) for LOST SOUL 6.
-Go all the way to the right and enter the shrine to automatically pick up LOST SOUL 7.
-Move to the serpent's path and examine the boulder.
-Type in "cat" (no quotes)
-Examine the third fox statue you come across to find a new path, then take it.
-Examine the gravestones on the left, then choose to trace the letters.
-Answer "Groom" for LOST SOUL 8.
-Examine the flowers in the middle and choose to pick a single flower.
-Go back to the main path and continue to the right until you find a fox statue with a red flower.
-Examine it and use the blue flower on it.
-Move all the way to the right to enter the shrine.
-Examine the shrine.
-Choose to retrieve the box.
-Ask "Were you killed here?"

SUSPENSIVE ACT
Team up and use the gun to shoot The Departed.
Team up and shoot The Departed in the face.
SURVIVED!

-Run all the way back to the infirmary.
-Talk to Yasuoka and ask about all topics.
-Go to the clock tower.
-When ready, choose to solve the mystery.

NOTE: CHOOSING ANY OTHER COMBINATION OF ANSWERS HERE WILL RESULT IN THE BAD ENDING. You'll want to reload a save prior to this point for that achievement if you want it.

-You will asked about three suspects in a row. Choose "Are" for the first two, and "Not" for the last one.
-Go upstairs to the second floor.
-In this next sequence, use the ladders in this order: Up, down, up, down, up.

SUSPENSIVE ACT
Hold the dried-up frog toward the insects.
Choose to eat a little bit of the doll's head.
Carefully present the crimson dress.
Smear the vermillion ink on The Departed's teeth.
SURVIVED!

-Talk to Yasuoka.
-Say "I think so".

The final choice is up to you.

Chapter is selectable by choosing Extra Content on the main menu once you've completed the game.

-Ask all questions
-Assist her
-Ask her some questions
-Go to H Elementary School
-Ask about all topics
-Talk to Hazuki again
-Go to Manhole Street
-Ask about all topics
-Talk to Hazuki further
-Go to Konoehara Academy
-Ask about all topics

SUSPENSIVE ACT
Use Abe's Information to show that Adam Love is Kaoru Hazuki.
Point to Hazuki's hoodie.
SURVIVED!

-Choose to show Hazuki your work area.

To get the true ending, you must have already completed the game once with the good ending. After that, select Continue -> Chapter Select and choose chapter 6.

All of your allies need to be alive, luckily the game will prompt you to change their fates if you'd like, so you can set them all to alive if necessary.

From chapter 6, proceed normally until you talk to Sakamoto inside the faculty room.
-Choose "The Douryou and Kinukawa thing"?
-A new prompt appears, choose "Try to convince her"

Follow the rest of the chapter 6 and 7 guide as written above - make doubly sure you react in the clock tower's suspensive act at the end of chapter 6 non-violently.

If done correctly, the first suspensive act of chapter 7 will not occur. After the final suspensive act, a new scene will occur. Choose to "Return to the clock tower" for the true ending.