- v1c6 by Tranquil SpringMar 27, 2011
- v1c5 by Tranquil SpringFeb 27, 2011
- v1c4 by Tranquil SpringFeb 5, 2011
- v1c3 by Tranquil SpringMay 23, 2010
- v1c2 by Tranquil SpringNov 9, 2009
- v1c1 by Tranquil SpringAug 16, 2009
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.