Shy Yaya spends her time in awkward conversations with her handsome classmate, guitarist Moriyama; dressing up with fellow fans of the rock group Juliet; and avoiding her bitter, sadistic ex-friends. 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, Shôhei, sets his sights on Nana. He is rumored to have close ties to the music industry, but instead harbors a secret agenda.