Denkou sneaks into Astro's school while invisible, eager to observe other children and their class activities. They are soon discovered after school, and they quickly befriend Astro and his friends. Denkou had no concept of good or bad because of their initial upbringing under Skunk, and they even brought Astro stolen polished gems as a gift. Denkou was so naive that they allowed Skunk to attach a bomb-rigged belt onto them as part of the "game". However, Skunk left them for dead after stealing a crown, only saved at the last minute by Astro. Denkou then goes back to Switzerland with Dr. Emil, still friends with Astro and his classmates. Denkou appears briefly in episode 48, watching Astro's speech with Dr. Emil, implying that he is raising Denkou like his child.