The main character is stopped from commiting suicide by a strange girl.

From Yuri-ism: Note – Despite the lewd cover and it saying its 18+, this doujin is pure.

One day, a girl was given a beautiful locket by another girl who said that it represented herself. All the girl now wants is to find the locket's creator once more, and her search leads her to Kitamoto-sensei and her Handicrafts club. However, Kitamoto-sensei seems more than reluctant to help her...


[by: Anime-Planet]

Aboard a spaceship there is a group of girls gathered together on top of the school's roof for the last time due to an impending meteor shower.
-
The end of the world is coming and a bunch of girls gather on the roof to greet their death.

Two stories parallel each other. In one, a student confesses to her sempai, in the other, new student Suzuki Chieri comes to the school. The two girls are kissing when Chieri sees them, as she walks around the school. But, as she watches them making out, she can't help but notice that one of them is looking back at her!
(Source:Okazu)

This story lets us look into the relationship of Matsuda Otome (a home schooled girl) and Nakagawa Minato (a high school teacher). Otome has been through a difficult past and is now under the care of Minato-sensei. Otome becomes suspicious of Minato's day-to-day routines and investigates. What will Minato tell Otome when she confronts her?