Mysterious Hero is an episode of Parappa the Rapper the Series from season 3.
The story starts when Parappa gets home, and finds Pinto and her friend Trina on the sofa watching cartoons, Pinto says that later they're going to study for a math test, and Trina says she's already got it, leading to a flashback of her refusing to study, saying she's got a natural gift. Sally Anne Bo Jumperdink comes over, showing him her painting of a deer. She then shows him her project for her school. The next day, Trina naturally messes up and Sally gets a fail for copying her drawing's face off of the face of a movie star. That afternoon, it's all over the news that a someone in samurai armor managed to get in the way of a robbery and slow the culprits down enough for the police to catch them. Nobody knows his true identity and the gang tries to find out who he is.
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