Moriguchi Oritō School of the Fine Arts

In the future, a man named Sakura is destined to create the technology for eternal life, which (due to Sakura's lolicon tendencies) freezes all women's aging once they turn twelve. God refuses to allow this, so he sends his angels to the past to kill Sakura before he can do this. But one angel, Dokuro-chan, decides to try to change the future without killing him. Problem is, Dokuro is very temperamental, and is constantly killing Sakura (and lots of other people too) in incredibly bloody ways with her giant spiked club. Good thing she can bring people back to life - if only to grusomely kill them again the next time she loses her temper.

Moriguchi Orito is transferring to a new school, but being lost in the fog he can't find his way to it and end up bumping into a beautiful girl and got struck by a vision of her in a very sexy pose. Seeing him with his cellphone in his hand, she thinks he took a picture of her and runs away crying, "My life has ended!", dropping her own cellphone in the process. Finally finding his way to the school, he realises that it's full of very weird people, and that his new seat is next to an empty desk where a bag is hanging with the same strap as the one on the cellphone the beautiful girl dropped…