An exceptional marksman and hopeless playboy, private eye Ryo Saeba reluctantly forms an alliance with his late partner’s sister to investigate his death.

During the Heian period, Abe no Seimei trains in magic but lacks interest, until a collaboration with Minamoto no Hiromasa arises to solve a strange phenomenon.

In the future, the Japanese government captures a class of ninth-grade students and forces them to kill each other under the revolutionary “Battle Royale” act.