Ryuusei Kumada attends Kunpō High School as a third-year student, marked by a distinct cross-shaped scar over his left eye. He formerly led the school's delinquents until Omi Kiriyama succeeded him in that role. Ryuusei's true nature is that of a bear spirit. Upon graduating, he changes his name to Suisei Kumada and re-enrolls at the same school as a first-year student.

The name Ryuusei translates to "meteor" or "falling star," while his new name Suisei means "comet." His surname Kumada combines the characters for "bear" and "field" or "rice paddy."