Once upon a time, the second Momotaro went missing while hunting down a demon girl. His sister Momoko, the last successor to the Momotaro clan, is not yet strong enough to be the third Momotaro. Today, in exchange for not being able to pay her taxes, she is fucked and creampied by the demons. In the middle of this, she is also raped by the second Momotaro, who has been brainwashed by the demons. Determined to get her brother back, Momoko trains her vagina to extract the source of the demons' power, their "essence," and heads off to the final battle...