In 2019, Urasawa said that he had the ideas for the characters and "Master Keaton" was very much based on that. He was also going to write the manga in addition to illustrating it, but because he was already writing "Yawara!", the editorial team was concerned about a young artist being able to create both. They brought in story writers, but the stories they proposed did not match Urasawa's vision. So instead meetings were held to create stories for the manga. But eventually the editors changed, and these "intimate" meetings were no longer possible. This is when Urasawa took the lead on writing the stories. He said that for the last two volumes, it is fair to say he came of with the stories alone.