Zebraman

Junior high teacher Shinichi is a failure at life. His wife hates him, his daughter is slutty, and his son spends his days being bullied. Shinichi spends most of his time daydreaming about his favorite TV show from his childhood, "Zebraman" (think "Power Rangers" on drugs). Eventually he begins dressing up as Zebraman and going out into the city streets at night. At some point he meets a villain named Crabhead and kicks him unconscious. Then the aliens invade and begin possessing people and killing young girls, turning Shinichi into a superhero, whether he wants the job or not. Oddly lighthearted for a Takashi Miike flick.