A failure as a 3rd grade teacher and a family man, Shinichi Ichikawa lives with his cheating wife, his teenage daughter who dates older men, and his son who is bullied because of his father's presence in the school.

Escaping from everyday life, Shinichi secretly dresses up nightly as "Zebraman", the title character from an unpopular 1970s tokusatsu TV series which he watched as a child before it was canceled after the seventh episode.

As a result of meeting a wheelchair-using transfer student named Shinpei Asano, also a fan of Zebraman, Shinichi not only regains his love for teaching but also develops feelings for the boy's mother.

On his way to Shinpei's house in his costume to give him a surprise, Shinichi fights a crab-masked serial killer whom he defeats when he starts exhibiting actual superpowers.

Though he knows how the show ends (with Zebraman's death and the villains victorious), Shinichi defies his predestined fate as he is the only person who can stop the aliens from taking over the Earth.