Mamoru first appears in Act. 38. He is under the delusion that Yukinari and his friends are villains and tries to defeat them as Mamo-Red. He ends up destroying the Mizuno High School building, but he blames it on the main characters. He returns in Act. 39 trying to have revenge, but his attempts end up causing property damage across the town. In Act. 40, the gang learn why Mamoru is so obsessed with cleaning messes and try to make him feel better about himself by pretending to be new recruits for the Mamo Rangers. It didn't go very well. He appears in Act. 46 suggesting that the school play be about the Mamo Rangers. In Act. 47, he appears in the play as a weed. He appears once more in Act. 60, where he tries to help during the mosquito outbreak. His penultimate appearance is in Act. 66,