21 parts Complete Whenever your soulmate is in deep thought about something, that thought tattoos on your wrist. When you kiss your soulmate, a heart shape tattoo appears.
Hajime Iwaizumi and Tooru Oikawa had this imprinted into their brains since they were kids; that they would find someone perfect for them. Someone who completed them.
But maybe that someone is a little closer to home.
(Horrible cover art made by me, please don't repost)