Fuyuki's dream of Keroro successfully invading seems to come true as the platoon begin to act with uncharacteristic determination.

The Keroro platoon opens a hamburger store. Everyone makes hamburgers of their own style, with Tamama putting a lot of sweet potato dangos in his burger, and Giroro putting gross ingredients in it, saying "If you can't even eat this, how will you survive on the battlefield?". Fuyuki and Natsumi help them too, Natsumi helps Mois with strangely selling "smiles" that give you motivation, and Fuyuki helps with burgers. However, Keroro orders new ingredients and has to pay a very huge amount of money for them. After doing that, they finally find out none of the burgers have been sold, but only the smiles have been selling, so the plan fails.

Fuyuki and Natsumi see Keroro sneaking around on the streets. When they think he's planning something suspicious, they follow him to a dead end. Fuyuki opens a closet, and falls into a hole along with Natsumi, leading to a secret city called "Alien street". They meet Keroro and the others there. However, Pekoponians are illegal in Alien street! They disguise themselves as aliens, and explore the city.

Keroro finds out Natsumi and Fuyuki have a health inspection on their school. Knowing this, the platoon invades the Health Inspection and punish the children in many ways. When Natsumi finds out, the platoon runs for it, but later gets caught by Dororo in a trap. Dororo reminds Keroro of him abusing Dororo in the Keron Army health inspection, and almost makes them suffocate, when Natsumi arrives and is about to attack. Keroro calls Dororo "most popular and loved dororo heichou", with Dororo getting all happy, not realizing he has been tricked. The platoon runs for it, with Natsumi chasing them. They get chased into the boy's changing room, where Natsumi can't go. Fuyuki accidentally gets knocked out of the door, and is seen in his underwear by all the girls on the school.

Tamama wakes up, seeing his tail is gone. Not knowing what this means, he asks the other members of the platoon, and they explain he has become an adult. When Kururu mentions that he's now ready to "Drink, hit, and buy", Tamama explores the adult part of Alien Street to find the meaning of it. In the end, it seems that while he was asleep, the "If you can live life over again gun" fell out of a closet and fired at Tamama, making him an adult.

Keroro perfects his shoulder massaging technique in order to gain Aki's appreciation and pay.

Keroro falls gravely ill with a mysterious illness.

Koyuki Azumaya has an eventful sleepover with Natsumi!

Keroro learns of Natsumi's fear of slugs, and turns a slug into the action hero Wettol King to fight her.

A pair of alien kids arrive on Earth seeking revenge for their father. Giroro trains the brother while Keroro, Tamama and Mois search for the kids' target.

Keroro directs a movie wherein he battles Nyororo using a robotic counterpart.

Keroro battles Natsumi for right to take a comfortable bath.

Giroro trains the platoon in the mountains, while Natsumi and Koyuki enjoy a school trip to the lake.

Keroro and Fuyuki compete in a swimsuit contest/eating contest/swimming race/footrace.

A bored Keroro goes around looking for DVDs to watch, but there's nothing his friends have that he likes, until he spots a DVD on Kururu's desk with warning signs on it. He plays it to find that this DVD is no ordinary DVD. A Tiger Horse appears outside Keroros room whenever he opens the door. But people can come in from the outside normally. Soon everybody is trapped in the room, and nobody knows how to get out until they get out of the room by going inside of keroro's picture door which is actually exit and no Tiger horses But He realize the everyone is tiger horses.

While visiting Grandma Hinata's house, the platoon find an alien that can shapeshift into anyone's worst fears.

Keroro ruthlessly tries making the most of his meal at a conveyor-belt sushi place.

The platoon once again let their copy robots take care of the house while they plan for fun activities, but things once again spiral out of hand.

The group follows Giroro to his secret vacation spot: a sweet potato field.

Sn unsure assassin-in-training has trouble finding the nerve to challenge Dororo.

Keroro loses his voice, and his friends go overboard trying to dub in his dialogue.

A god from Keron comes and chases Karara and Chiroro to Pekopon. He is angry, and the Keroro platoon try and calm him down, but their efforts make it worse. And he has been known to destroy planets in his angriness.