Pian's mother calls her son to inform him that she'll be home late because of the rain. Pian ensures his mother that he can take care of himself. In an alleyway not far from Pian's mom, a robot overhears her saying not to make a mess, which angers him. Amato and MechaBot are talking in the garage when Pian calls the former to hurry to his place because someone is trying to break in. The lights shut after Pian drops his phone in fright, he meets a robotic intruder's glowing eyes, and the line gets cut off. Upon reaching Pian's house, Amato uses his mechanized umbrella to fly over the locked gate.
Amato still receives no response at the door. Deep appears, having come over to return Pian's video game. They hear a call for help from inside, and MechaBot finds a side door for them to enter. Amato combines MechaBot with a vase to make a Mechazooka, and they tiptoe up the stairs. They hear ominous whistling, which Deep thinks to be ghosts. Pian finds them, and tells them to run, but the robot lands at the top of the stairs and deflects two Mechazooka rockets out the window. MechaBot is frightened to recognise Janitoor, and they all just manage to flee down the stairs and into another hall.
Pian leads them to the storeroom to hide. Amato asks for information on Janitoor; Rubika says he's a cleaning robot and the former undefeated champion of the space arena, MechaBot elaborates that he only stopped from retiring of old age. While Deep continues to speculate what may happen to them from media he's watched, Pian lights up the storeroom with the power switch, astounding his friends with how big the room is. They board the elevator, but Janitoor breaks in from the ceiling. Mechamato blocks him from Pian, but when Amato accidentally alludes to his old age, the enraged Janitoor activates his upgraded form and throws everyone out the elevator door.
Janitoor throws a wet floor sign ahead of them that makes the entire floor slippery, and he cleans the hall as he slides across it. Mechamato utilises an ironing board as a surfboard to aid his bumbling friends. Pian points him to the kitchen, where Deep questions how messy it is. When Janitoor catches up to then, MechaBot trashes the kitchen more to distract Janitoor into tidying up the mess as they flee to the bathroom. Pian's friends are enamored by the vastness of his house, but Pian says his perceived wealth is his father's instead.
Janitoor finds them, and Mechamato gets thrown into some workout equipment. When he's told that he's not strong enough to defeat Janitoor, Mechamato uses the equipment to become Mechamacho, putting him on equal footing with Janitoor. A punch across the room returns another, until Mechamato throws a barbell at him, crashing him against the wall. Janitoor admits defeat and asks to be ended, per Space Arena tradition. Amato says Earth doesn't go by those rules and spares him. Pian's mother returns and is surprised by how clean the house is, which Pian credits his friends for. She thanks them, but a jar of cookies falls from her bag, angering Janitoor all over again.
This episode provides examples of:
- Angry Fist-Shake: Janitoor, compelled by his programming to clean up the mess made to distract him in Pian's kitchen, angrily shakes two of his four fists at the humans running away as he cleans.
- Barbell Beating: Mechamato combines with gym equipment to turn into Mechamacho in order to become strong enough to fight Janitoor. His final attack has him spin a dumbbell to deflect his pressure washer attack before throwing it at him, which pins Janitoor against the wall.
- Beat It by Compulsion: MechaBot trashes Pian's kitchen to distract Janitoor, the raging cleaner robot, who prioritises taking care of the mess over the chase, but not without contempt as the others escape him.
- Defeating the Undefeatable: Amato and MechaBot are initially reluctant to take on Janitoor since he was the undefeated champion of the space arena for 5 consecutive years. However, after Mechamato mechanizes with Pian's gym equipment, they become strong enough to defeat him.
- Disproportionate Retribution: Janitoor responds to people making messes by attacking the culprits. Implying that he's old also brings a similar reaction.
- Dual Wielding: In one instance, Janitoor wields two large toiletbrushes at once as weapons.
- Eyedscreen: When Amato shoots a Mechazooka blast towards the bad robot infiltrating Pian's house, a zigzag-shaped letterbox closes around his eyes, and then MechaBot is frightened to recognise him as the fearsome Janitoor.
- Face Palm: Pian slaps his forehead in disappointment at Deep overdramatising them being hunted by Janitoor off of something he learned from movies.Pian: [facepalms] This kid needs some help!
- Here We Go Again!: The conflict is caused by Janitoor being so enraged by Pian's mess that he attacks him. The heroes eventually manage to subdue him and get him to help with cleaning up. At the end, Pian's mother accidentally drops a jar of biscuits on the floor, spilling its contents and sending Janitoor on a rampage again.
- Honor Before Reason: Implied for Janitoor, who puts up a solid fight against Mechamato whilst still knowing when to admit defeat, even when he follows the belief that defeat (in the arena) deserves death. He even expects the hero to kill him, but when Mechamato spares him instead, Janitoor is immensely grateful.
- Hover Board: Amato uses a mechanized ironing board to traverse a wet hallway. Fittingly, steam comes out the back.
- Multi-Armed and Dangerous: Janitoor's upgraded form grants him additional mobility and a sort of Mini-Mecha which adds two larger arms that he can use along with his default arms.
- Red Eyes, Take Warning: Janitoor is first seen from the shadows by his red Glowing Mechanical Eyes prior to attacking the humans. Even after he reforms, seeing someone make a mess has his eyes turn red to the sound of escaping steam before he starts rampaging again.
- Rocket Punch: Mechamato throws a punch that is enhanced by a rocket at his elbow, hitting Janitoor hard enough to send him across the room.
- Sinister Whistling: Janitoor is fond of whistling ominously while on the prowl. The lights in Pian's house go off shortly after he hears his whistling, then Amato, Deep and Pian hear it again before Janitoor laughs evilly and attacks them.
- Spin to Deflect Stuff: In the Mechamacho form, Mechamato spins a dumbbell to deflect the hot water of Janitoor's pressure washer attack.
