At the tender age of five, Shinsou lost his family to a villain attack. The day he was put into foster care a piece of a clover showed up on his wrist. Kids that lost their parents or was abandoned, had a soul family mark show up on their wrist along with their soulmate mark on their shoulder. The mark was for the family you were designed to be with. Normally a couple who couldn't reproduce would have the mark and look for a child with the other pieces.