Naota goes from high school nothing to mutant warrior in the blink of any eye. But what does it all mean? The town stirs with gossip when the Mayor's adulterous affair makes headlines. But his daughter, Ninamori, the class president and Naota's friend, is having a hard time of it. So hard, in fact, that she turns into a giant balloon to challenge Naota in battle...

Naota's life is not simple. He lives with his eccentric father and grandfather in a city distinguished by a gigantic hand-iron shaped factory perched on a hill. His brother's ex-girlfriend makes passes at him. And to top it all off, an impish, playful alien has run him over with her Vespa and smacked him in the head with a bass guitar! Little does he know that this is only the beginning of his involvement in an interplanetary ideological war.

Naota's father witnesses an unpredictable kiss between Naota and Haruko. Displeased with this development, he challenges Naota to a winner-takes-all duel! Not wanting to disappoint Haruko, Naota accepts the battle. Meanwhile, Mamimi's demeanor has become a bit more than eccentric. Could it possibly be... jealousy?