BxP Anx

Inside a crowed train, a punk boy, You, is for some reason protected by a (dotekaku kakkou ii) B-boy. The B-boy, Makino, carries away with him a precious stone that You had unknowingly dropped. He comes to ask You, who had ended up moving in Makino's home after much confusion, if he has any memory of himself. Has he met Makino is the past?! You was...