"Backpack" (ランドセル, Randoseru, Tonari: 138) is the 97th chapter of the One-Punch Man manga series.
Child Emperor is walking down a passageway and monitoring what the other heroes are doing. He notes that Flashy Flash's transmitter seems to have failed. A monster tries to ambush him only to be shot dead by one of Child Emperor's robots, Mini Octotank No. 8.
He then finds the remains of the destroyed Metal Knight robot and notes that someone appears to have attempted to reassemble it and has dissembled some parts with real expertise. He is concerned that there may be robotics experts working with the Monster Association and the technology that was developed to fight monsters may end up being used against heroes themselves. He then decides to try salvaging some information from the remains of the robot in hopes of finding out where the hostage, Waganma, is being held. The robot yields a detailed map showing where the hostage is held and Child Emperor is angry that Metal Knight has refused to share this information despite knowing it. He calms himself and unwraps a sweet to eat when he realizes that Octotank has been destroyed by Phoenix Man, who asks if he was here to play.
Phoenix Man monologues about his role within the Monster Association and his backstory before attacking Child Emperor, only to run hard into an invisible shield. As the monster reels in pain, Child Emperor notes that this was a lightweight shield that he'd developed and which could be folded and even wrapped around sweets. He then executes Phoenix Man with an array of tools that spring out of his backpack.
He rescues Waganma by gassing the monsters guarding the hostage's cell while protecting Waganma with a frog-themed gas-mask. As they are about to leave the cell, Sludge Jellyfish oozes in and attempts to crush Child Emperor, only to realize that this is unsuccessful as Child Emperor has put up a shield generated by his umbrella. He tries to cut up Sludge Jellyfish before defeating the monster by dousing it in liquid fuel and setting it alight.
As the two of them escape, he notes that something appears to be up ahead and sends a toy tank as a sentry. The tank is destroyed and Machine God G5 appears. Child Emperor attempts to disable the machine using a high voltage cage and a jamming signal, but G5 defeats it easily. The chapter closes with the machine approaching the pair of them menacingly.