The girls are watching the Harajuku Air Show. Rudie was able to get them booked as the ending act and reveals that he got VIP passes. He notices a few weird devices, which turns out to be Marshmallow Rockets introduced by Colonel Spyke. Spyke introduces the girls to Captain Manly and shows them the new Mecha Robot named "Bad Boy".
Baby wants to play in it, but the other girls advise against it due to her being young, which in return makes Baby upset. She volunteers to be the co-pilot but Captain Manly shoots down the idea. They decide to take a picture, but when Rudie jumps in the shot, he knocks Baby and Captain Manly inside, knocking unconscious the latter.
A news bulletin flashes on a nearby television monitor where a flying saucer is seen over Harajuku Harbor, and dove-like aliens fly out of it. Colonel Spyke asks to girls to help while Baby is still trapped inside the robot.
While exploring, she befriends the computer terminal which she names "Lucky". Back at the harbor, Colonel Spyke announces she's the official alien welcome wagon. Rudie sees this as an opportunity to expand a new market. Back inside the robot, Baby plays a game on the terminal before Lucky interrupts with a notice that alien lifeforms have landed. She views the security cameras and notices different looking aliens than the one on the news bulletin.
The aliens at the harbor broadcast a looped message that they come in peace and want to discuss inter-universe travel and the secret to perfect skin. Baby finds it suspicious that two different aliens visited Harajuku in one day. She asks where everyone is and Lucky responds with Harajuku Harbor and points out the airfield is left unguarded which Baby suggests was the plan all along.
She attempts to control the robot but the signal is being jammed and the only way to access power control is through fingerprint authorization from Captain Manly, who is still sleeping. Baby drags him over and places his hand on the scanner, successfully unlocking further options. Rudie, whose paddling out towards the UFO, notices an alien fly by and immediately pursues it.
The bug-like aliens, using vehicles and parts found at the airfield create their own robot, which meets face to face with Bad Boy. They begin fighting but Bad Boy is immediately taken down. After quick recuperation, Baby (with the guidance of Lucky) are ready to fight. Out at sea, Rudie struggles to capture one of the aliens. He manages to latch on to one, and it starts. After vaporizing one of the robots, the bug aliens start re-targetting the marshmallow rockets to attack Harajuku Harbor, where everyone is at.
As Rudie rides the alien he attempts to scan his card over the beam of light expelling from its' head, which removes the illusion of the UFO at the harbor. He begins doing finger puppets over the projection.
The man operating the radar notices a marshmallow missile heading directly for them. In addition, "Bad Boy" is being piloted by a little girl who are currently in pursuit of the marshmallow. They are able to deflect the marshmallow into the alien that is following them, causing it to fall into the ocean. Captain Manly regains some consciousness and manages to press a button that causes a system wide power failure, sending Bad Boy into the ocean.
Captain Manly emerges and takes credit for the defeat of the aliens, when it was Baby who piloted Bad Boy. Baby said he can have the credit, she just wanted to be with her friends. Music, who isn't satisfied, walks over to Bad Boy and knocks into it's arm, and a drop of marshmallow splashes on to Captain Manly's head while the rest of the girls laugh.
This is the fifth time Baby was featured on a title card.
The game Baby plays on Lucky's terminal is similar to Frogger.
This episode is similar to the show Big Guy and Rusty the Boy Robot.