In a world of magic and technology, a lonely demon finds himself cursed with boredom and meaninglessness as he is unable to die. Trapped in his human form, his ultimate power is sealed within a black crystal in his chest where there, in a normal person, usually would be a heart. Tatsu Banmō (万亡竜), a.k.a. the demon of chaos, passes the outskirt on his quest to finding a purpose in his immortal life when he meets a fine young lady, Tenko Toshinori (俊範天子), in the Lake Village. As Tatsu is being followed, Tenko ends up getting involved in a case between Tatsu and some mysterious mages; a case that was none of her concern. Deciding to pull Tenko out of the mess he brought her in, Tatsu soon learns about his purpose and embarks on a journey towards finding eight magical crystals, each equipped with a special ability and dominated by a unique emotion. Accompanying him he has his fellow companion, Tenko, and his servant through many decades, <insert name here> (insert Kanji here).