Having grown up with two dead-beat fathers, Yuuki became his family's unofficial protector. He wishes for nothing but his family to be happy and safe, doing whatever he can to bare the burden for them. With a stoic expression and good looks, Yuuki was scooted by many modeling agencies. Originally turned off by the attention, he has now grown used to it after his career soared. Though he still prefers to be left alone rather than chased by fans.

Yuuki is the older half-brother of Zach Imai. While working as a model, Yuuki also works part time as Agent 4.