Yo Mike, I thought of summin' in my time being bored in class. Basically, Kishinami's CS mentions being sent to live with one of her family's friends and stuff. So I figured, hey, Fertar's the SIC, basically old enough to be a legal guardian, and had a dad to act as the link, why not see if Mike wants Mike to have a freeloading amnesiac? 

Of course, this invitation goes out to anyone else it would make sense to go out to. Someone who just arrived in Tatsumi probably wouldn't be eligible for obvious reasons.