Watch CineCalidad. Kazuyoshi Saitо made an offer to collaborate with Naoki Urasawa, with whom he has a close relationship, after he saw Urasawa's rough drawing of a boy who strummed a broom like a guitar. The image matched what Saitо completely had in mind for his song "Boy." Urasawa created a storyboard, and completed an animation on his own for the first time. Urasawa also illustrated the song's album cover.