After getting zapped by a machine created by Arima and Tenma, Rokuro goes back to being a three year old. Soon after the zap, the machine gets broken down. Now it's Seigan, Mayura, Benio and Shimon's job to take care of him while Arima and Tenma try to fix the machine. Lucky for them, it doesn't take as long as expected. - A mini story with the characters from the anime, twin star exorcists