You're the Star! Urashima's Turtle Boy

Synopsis

Eiichi's class is putting on a stage play of Urashima Taro for the school festival. With Butagorira as Urashima, Miyo-chan as the princess, and Eiichi cast as the turtle, tensions run high when Butagorira rides on Eiichi like he's a horse. An angry Eiichi decides to change the story entirely and travels back to the Muromachi era on his Chronological Machine. Eiichi seeks out the original author of Urashima Taro to make the turtle the main character, but things don't go as planned...