Isamu/Other Media

Numbers
Child Emperor and other heroes tried to stop Jumping Spider together, but were easily blown away by the creature because of a misunderstanding of the monster's real capability. Jumping Spider is later defeated by Saitama, but King was given the credit. He measured the heroes' rating while they were there. Bang refused, Genos was not able to be measured due to his robotic parts, Fubuki got a low rating, and both Saitama and King got an undefined rating. The Okame-Chan had its limits for being too weak or strong. Child Emperor called King the strong one and Saitama a lazy person.

The Murder Case That Is Too Impossible
Child Emperor and other S-Class heroes were invited to a hot spring resort, after the Dark Matter Thieves failed invasion. After the hot spring, Sitch gathers all the heroes into a celebration of the victory against the invasion. Some heroes became drunk after drinking the sake and disgusted Child Emperor. He made small talk with Zombieman whether or not he's enjoying himself. The next day after the ceremony, the heroes find Zombieman murdered, stabbed in the back by Atomic Samurai's katana. Child Emperor states that one of the S-Class hero is the culprit. As he investigates the murder, he gathers evidence and information from the heroes and tries to eliminate one and another to find out the truth. He interrogates all, including Saitama and finally King, but was scared off by his King Engine. While the investigation wasn't progressing, Tatsumaki tried to restrain everyone, until Zombieman suddenly woke up. Zombieman later revealed that Atomic Samurai's katana was floating with green light surrounding it similar to Tatsumaki, when it stabbed him. Child Emperor questions Tatsumaki, but she angrily denies it. Zombieman didn't care what happened the night prior and the heroes disbanded and the case was dropped. Later Child Emperor was called by Sitch to look at the surveillance camera footage of last night. It was shown that Tatsumaki did in fact stab Zombieman, while heavily drunk.

One Punch Man: A Hero Nobody Knows
Child Emperor is a playable character in the video game, One Punch Man: A Hero Nobody Knows.