Mio's not really a tomboy, but — hmm. So, to my reading, New Generations are kind of three versions of the girl-next-door archetype. Uzuki is the ordinarily cute sort — frills and long hair, works hard but doesn't really get anywhere by it. Rin is the cooler-than-you type, sleeker and more stylish. Mio is the girl who grew up with brothers — played with the boys as a kid, but she'd never be mistaken for one, and still super-friendly with everybody.