Homura Tsukishima and Sakurako Hirosue are roommates at Principia Academy, a school located on an island created specifically for researching "shiki", which is a form of power created by manipulating numbers.

Mashiro-hime has just transferred to the all-girls school, Garderobe...but little do the other students know, she's actually a boy. Desperate to escape an all-boys school where he was looked down upon, he...

In response to signs of an impending invasion by alien conquerors, five young people have undergone modification surgery in order to gain the strength to fight them off when they arrive. There's been no sign of...