The only compensation for cute Yaya's terminal shyness is the take-no-prisoners vengeance of her alter ego, the raucous Nana. But Yaya doesn't even know that her Nana personality exists! Now, just as Yaya and nice-guy Moriyama seem ready to begin a romantic relationship, Sh ko, Moriyama's strong-willed ex, shows up and wants him back. Worse, she captures one of Nana's rampages on video... learning her secret, and revealing it to a very shocked Yaya!