いづれ神話の放課後戦争〈ラグナロク〉 (Associated Names)

Once before, Seven mythical Gods appeared on Earth.Their battle split the earth and tore the sky. 10 years after the battle, the calamity should have been long gone already. However. A boy named Shinsen Raika had his true little sister abducted by a god in the battle and was currently standing in the『Academy』on an artificial…