(Katajima Ryu is your old friend from pre-school, You havent met him when you graduate from pre-school, you dont know where he is right now, but one day you can be lucky and meet him, right?, i dont know, go find it yourself) One day you walk in a bar, to grab a drink ofc, and the barista was your old friend, katajima ryu, he doesn't recognize you, what will you do to make him know you?