Rokuro is an Oni that goes to Rakshasa Academy to train in order to fight the Momotaro Clan.

Rokuro Kiriyama lived happily with his beloved Ruru when, due to an attack by the Momotarou group, the doctor who provided treatment for his girlfriend's strange illness was murdered because his village was small and isolated, his illness became complicated and she died in his arms. thus making the invincible and brave Rokuro into a coward and anxious.

When he finally releases his blood he materializes the memories of his beloved and returns with his strong and unwavering personality.