OFFICIAL EXPLANATION:
fooly cooly, or furi kuri, is sort of like a pun/play on words in japanese. It means three things: chestnuts, kneading bread, and tweaking someone's boobs.
the three of them are adressed in episode one, and bread is a recurring theme.
i'm not sure how exactly it applies to the show, the breast tweaking is sort of like a metaphor for growing up, y'know, becoming interested in sex and stuff. the underlying theme/moral of the story is that naota-kun is the most mature of everyone, because he's not afraid to be a child. other people put on airs to be more mature (amuro, for instance), but naota allows himself to live out his childhood while he can.
Mach mich eine semmel, schlampe!