Futagoza no Paradox

Eiman Gakuen is the only school which has a program to help develop the special abilities of the students. A pair of twins Souji and Souichi attend the school with their childhood friends Natsuki and Haruki, as well as other friends. However, their normal days came to an abrupt end when one day after school, a thunderbolt struck the school and sent Souji, Natsuki, Ao and the entire school itself to another dimension.

[From Hau~ Omochikaeri!]