Welcome to Endings and Acheivements 101 for Fatal Twelve. Due to the nature of the guide, there will be spoilers, but plot points and events of the story and endings will not be spoiled here. The choices will be here.

Also, there are two ways to help you with ending hunting in this guide.
1. A text walkthrough written out for those who process that better. (Written out, Endings section)
2. Choices section, which shows it in a chart of sorts.

With that out of the way, let's begin!

Save every choice. One of the achievements requires you to make every choice. This is also helpful because you can just go to the saved choice for the ending you're after. Which leads me into my next tip...

Choices do not add up over time. You could make all your decisions in a certain way, but it has no effect on your ending. Only a few of the choices determine your ending. The others make no difference.

After your first playthrough, aside from an extra story at the start, there is new dialouge in the opening scene at the train station with Naomi. To easily find it, speed through the scene with skip old text only.

Your answer to Mahiru's confession is key to a lot of the endings. If you're on the right track, you should get a hint from her on that before the final trial.

There are 7 endings: 3 endings and 4 bad endings.

There are 19 total choices, but some endings will not have all the choices, so don't worry if there seem to be some you're missing. Once you've completed all the endings you should have all the choices.

There are multiple versions of some divine selctions. Once you get all the endings, you should have all the divine selection versions and CG's. Don't forget you can check all this in extra too.

There are 7 endings. 3 endings. 4 bad endings.
There are 19 total choices throughout the game, but in some endings you won't see them all. This section won't say the events in the ending, just the choices.

Survivial
While most choices don't have any real affect on the story, some will get you a different ending.
Many endings rely on Mahiru's confession. However, there are a few bad endings you might fall into along the way. Here's how to avoid that. To get here without ending up in a bad ending before you get here, you need to.. (note: these occur that different spots throughout, but they are in order.)

Turn down Odette (the other option leads to bad end 1)

Get in Touch With Miharu (the other option leads to bad end 2)

Answer the phone (the other option leads to bad end 3)

Hang Up (the other option leads to bad end 3)

As for Bad End 4? Well... you'll have to wait and see...

Ending 1: Future
The choice that triggers this ending is at Mahiru's confession.

Give her an answer
Put it off for now

Instead of giving her an answer, choose "Put it off for now."
After this, you are on track to the Future ending. This ending tells you the most about divine selection, Parca, and everything else.
Before the final divine selection in this ending, Mahiru will tell you something that will help as a hint to how to get the other endings that rely on your answer to her confession.

Ending 2: Fatal Twelve
This ending also relies on Mahiru's confession.
This time, choose to give her an answer. Then, select Accept her Confession.
Later... Your answer to whether you know the what lies inside you doesn't matter. Choosing that you don't will give you a little more information though. When asked what you want to do with your power, choose to Do Nothing. Once you've done that, let the ending play out.

Ending 3: Like a Dream
Follow the same steps as Ending 2 until the final choice. When asked what to do with your power, choose to Alter Fate. With that, your work is done and all that's left is to watch the ending.

Bad Ending 1: For Granting Her Wish
To fet this ending, when the choice pops up, Accept Odette's Terms.
After this, you are on your way to the ending.

Bad Ending 2: This is Another Story
When you get the choice, Leave Miharu Alone for Now. With that, you are on track for this ending.

Bad Ending 3: What is Your Purpose?
This ending has two ways to get it, but the choices take place in the same place.
When you get the phone call and the option, choose Ignore it. If you choose to answer the phone, pick Hear Him Out.

Bad Ending 4: Fated Ending
This ending relies on your answer to Miharu's confession.
When given the option, choose to Give Her an Answer. Then, choose to Turn Her Down. You are now on track to the final bad ending.

Fated Beginning
Start the game. Simple as that.

First Week, Second Week, Third Week, Fourth Week, Fifth Week, Sixth Week, Seventh Week, Eighth Week, Ninth Week, Tenth Week, Eleventh Week, and Twelth Week
...Week doesnt look like a real word anymore.
Complete that week and it's Divine Selection in the story. You should get the acheivement after that week's Divine Selection.
Not all endings will go through all the weeks.

Check The Situation
During the game, at the bottom of the screen, farthest to the right, open the menu. The icon for Card Book Mode is some of the Divine Selection cards. Click it and you chould get the acheivement.

Those Who Record Time
To open Summary mode, go the menu during gameplay and click the image of the notebook with the magnifying glass next to it. Once you are in the mode, you should get the acheivement.

Memories
Open gallery mode. On the opening menu, not during gameplay, click on Extra. This will bring you to Gallery Mode.

Colors
Get all of the CGs. You can check your progress from Gallery Mode. Except for one of the endings, which has no CGs, all the other endings will need to be complete to do this.

That Encounter
This extra story will play at the beginning after your first playthrough. This may only occur after getting the Future ending (or only after one of the endings) though.

As I already got everything and got Future as my first ending, I can't test this. If you have not completed any endings yet and are willing to, please complete either one of the other endings or one of the bad endings and report back in the comments. Thank you.

Skillful Listener
Select every choice at least once. I reccomend saving each choice before you make it so you can easily access them. It's not only helpful for this, but also for endings.

Observer of Fate
Get all the endings. Details on how is in the Endings section of this guide.

A Young Girl's Trail
Go to extra on the opening menu, next to Gallery, click Replay.

As the Title Implies?
Start the game twelve times. This doesn't mean to Start by using the Start option on the opening game twelve times but to start up the game twelve times.

Multilingual
Switch the game's lanuage.

Answer This does not take place when you are answering Miharu with options. This acheievement happens in the Future ending. Play through the future ending again (This may only occur when playing through Future again after completing all other endings, but I'm not sure and cannot test it. If you can please test this and let me know.), not on scene replay. You can use skip as long as it stops for new text. You should have one new line in the scene that you didn't see on your first time.

The Following Acheivements need you to complete a specific ending. The specifics on how to do that can be found in the Endings section of this guide.

Future
Complete Ending One.

Fatal Twelve
Complete Ending Two.

Like a Dream World
Complete Ending 3.

For Granting Her Wish
Complete Bad Ending 1.

This is Another Story
Complete Bad Ending 2.

What is Your Purpose?
Complete Bad Ending 3.

Fixed Destiny
Comeplete Bad Ending 4.

Here are all the choices. There are 19 points where you need to make a choice in total. Unless stated, the choice has no affect on the story.

Week 1

Let's have a look.
Better not mess with it.

Might as well sell it.
Let's take a look inside.

It's embarrassing, so... lemme go.
O-okay, then.

Week 2

As for things with Naomi...
As for things with Miharu...

Do you want to join?
I take it you're going to work?

There are no choices in Week 3.

Week 4

Talk to Her
Leave Her Be

I'm happy, too.
It's a bit awkward.

Week 5

I'll see you tomorrow.
Okay, take care.

Talk to her
Leave her be

Go home alone
Offer to walk with her

Week 7-1

Accept her conditions (Bad End)
Turn her down (Continue the story)

Week 7-2

"Naomi?"
"Miharu?"
"Mao?"

Week 9-1

Get in touch
Leave her be for now. (Bad End)

Week 9-2

Ignore it. (Bad End)
Answer.

Hang up.
Hear him out. (Bad End, This is the same bad end you get if you choose Ignore it.)

Week 11-1

Give her an answer
Put it off for now. (Continue the story and get ending)

ONLY IF YOU CHOSE GIVE HER AN ANSWER

Accept her confession (Leads to two of the endings depending on a choice after)
Turn her down (Bad End)

ONLY IF YOU CHOSE ACCEPT HER CONFESSION

I am
I'm not

Choose to alter fate (Ending)
Do nothing (Ending)

These are all the choices.

After you first playthough, in the opening scence with Naomi at the train station, when you run into the 'foreigner' there is new dialouge where Rinka and Naomi feel like they've had the conversation before. To find it easily, run through the scene with skip old text only on.

Welcome to the guide, I hoped this helped you out.
Please let me know of any errors and things I could do to make the guide better!
With that, happy playing everyone!