From Horobi no Michi:
Kirisaki Fumio’s just an ordinary highschool girl in love…
…but then she finds out that the guy she’s fallen for happens to like someone else.
And then she gets into a fight with a friend… that and various other things are getting her really down…
…so she decides to go out and get a chainsaw.
And take it to school.
And kill the boy she likes, and herself afterwards.
Along with anyone who happens to get in the way.