Kouta chanced upon a street brawl while making his way home from his regular hangout spot in Shibuya a few years back. The altercation involved an unkempt ice-cream vendor accompanied by a foreign youth, who stunned their attackers by knocking them out with ease. Over time, Kouta became acquainted with these curious men, but despite their growing friendship, he remains ignorant of their true identities, origins, and the secrets behind their pasts.