Ryo Takatsuki is a typical Japanese high school student, whose seemingly nondescript way of life started to unravel with the arrival of Hayato Shingu and Takeshi Tomoe, the new transfer students with a history of disciplinary problems. An unexpected chain of events that followed would change the life of Ryo and those around him, from his childhood friend Katsumi to the brash Hayato and the enigmatic Takeshi, who may yet turn out to be friends or foes. With his new found comrades, Ryo sets out to discover the secret of the mysterious A.R.M.S., which would reveal an unexpected destiny for each of them.