Shy Yaya spends her time with guitarist Moriyama. But whenever Yaya bumps her head or looks into a mirror, she changes into her other personality-boisterous, tough-as-nails Nana, who punishes the guilty and belts out Led Zeppelin tunes. Now Moriyama's mysterious adult friend, Shohei, sets his sights on Nana. And he harbors a secret agenda.