A certain Ultimate Alien Hero

A boy armed with the most dangerous alien device in existence suddenly finds himself trapped in a city where magic clashes against science, Espers walk the streets, and monsters hide behind human faces.

With millions of microscopic machines flowing through his body like living blood, the green-haired teenager is far more than human. His powers defy logic, his technology surpasses imagination, and the mysterious voice inside his mind constantly reminds him that this world is far more complicated than it first appears.

But surviving Academy City may be harder than fighting aliens.

Especially when he develops an unexpected crush on a certain short-tempered Electromaster whose sparks are just as dangerous as her personality.

Now caught between scientific conspiracies, magic cabals, underground experiments, and chaotic daily life, the boy soon finds himself dragged into the problems of an unbelievably unlucky Level 0, a tiny gluttonous nun capable of eating enough food to bankrupt entire countries, and a growing circle of strange allies and terrifying enemies.

As hidden organizations begin taking interest in the alien technology fused to his body, the balance between Magic and Science slowly starts to crack. Because the Ultimatrix was never meant to exist in this world...

...and neither was he.

Explosions, sarcastic banter, dimensional threats, awkward romance, unstoppable aliens, and enough chaos to destroy Academy City itself await in this crossover adventure where science fiction collides with supernatural warfare.

What could possibly go wrong?