A friend of
Junko_Minamoto.
Every circle of friends has at least one odd duck; Junko's little group considers Eri to be about as odd as they come. Most girls are interested in shopping, the latest trendy fashions, and the newest pop music. Eri mail-orders military surplus MREs, wears a flak-jacket over her fuku, and can recite dozens of old army songs by heart.
Still, she believes strongly in the camraderie of friendship and soldiers on through the various girly-girl things her friends want to do, stony-faced and serious. She tolerates their 'weirdness', so they tolerate hers. It's a working friendship. She's physically active and fairly bad-ass for her age; not only is she the top player on the tennis team, she's also the Captain already! When not doing that, she's often conducting her own personal 'war games', with her quoted reason for this bizarre behavior being 'preparedness'. It's worth noting that she only has access to toy and replica guns (and the others are worried for when she's old enough to own an actual gun) but otherwise real surplus equipment.
On the surface, she's cold-hearted and brusque, but the reality is that she has a very kind heart and her only real desire is to protect the people around her. Civic minded, Eri often volunteers at soup kitchens, homeless shelters, and the like. And, when Junko's mouth writes checks that it can't cash, Eri's usually the one to beat up the people her friend's pissed off.