This achievement is really easy, when the game is started, choose a girl.

For "Home" achievement, you get it when you have just started the game as well as you are already home. :'D LOL

Go on PC for "Chat" achievement.

Change the clothing before to exit from house, and once it's out getting the "Street" achievement.

Go into the car and to go school.

Once arrived to school, go to on bath (ground floor) for shooting the write, for chatting with girl on PC.

In the meantime, time passes, wandering around the school, not only to get to know the rooms well.

Why not only because it is still too early to go to class.

As soon as it is 10 o'clock:
1. 10AM: Go to class (first floor and first room)

2. 13PM: Go to class again (always the same class)

3. 15PM: Go to the dining room (ground floor, next to the school's main entrance)

4. 17PM: Go to class again (always same class)

5. Leave school and go home.

Change the clothing and to go sleep (only 20PM)

Since you cached the writing on the wall in the bathroom and now you can chat with her. :-)

Go on PC for chatting with girl. (the girl will tell you find the bear)

Change the clothing.

Go to school for finding the bear, it is on your left in a classroom next to the bathroom where you shot the writing.

Once you have the bear, go home.

Go to PC. (the girl will tell you kill the blonde girl but before you need the knife)

Go to school for knife.

The knife is at first floor, go to the first floor, once you get there at the first floor, go to your right and find the knife.

You can finally kill this poor blonde girl.

Leave the game and you can see that you have get all achievements. :-)