Naota is a detached sixth-grader afflicted by the pangs of puberty. When a crazed girl on a motor scooter runs him over and brains him with a bass guitar his life gets weird - giant-fighting-robots-shooting-from-his-skull weird.

Naota’s attacker, Haruko, is now his dad’s live-in housemaid and she says she’s an alien. Mamimi names the robot from Naota’s head Canti, the God of Flame. Does Canti have anything to do with the mysterious fires burning all over town?

The president of Naota’s class, Ninamori, is no stranger to the dirty deeds of politics. She rigs the vote to cast him as the lead role of their class play. But she gets in over her head after a crashing introduction to Haruko.

There’s a guy claiming to know Haruko and why she’s using Naota’s head as a portal for oversized battling robots. It’s too late, though, as a malfunctioning satellite is heading straight for them and it’s up to Naota to stop it!

Jealousy spurs an epic pellet gun battle between Naota and his dad over Haruko. The object of her desire will be revealed, and she’ll do whatever it takes to get him!

A hand statue looms over the Medical Mechanica building, threatening to iron out the city. As Mamimi’s new pet turns out to be a crucial element to Haruko’s plans, Naota finally proves that he’s no pushover.