He doesn't have to, she'll be like "YOU KNOW YOU MISSED ME!" Since she's been gone for a bit, herself. Though if she finds out he was living on the streets, she might not be too happy. I mean, last time she was in the city, Ango was practically doing the same thing, baka...

She might know OF the team that had things go so bad. Heck, it might be why she decided to become a Saver, instead of going off to be a Striker (since her powers were definitely leaning in that direction when I first had her in the game!). If that's cool with your backstory idea, that is!