- Sergeant Keroro
- Private Second Class Tamama (debut)
- Corporal Giroro (debut)
- Sergeant Major Kururu (debut)
- Lance Corporal Dororo (debut)
- Fuyuki Hinata (minor role)
- Natsumi Hinata (minor role)
- Momoka Nishizawa (cameo)
- Angol Mois (cameo; debut)
- Viper (debut)
The episode begins with a recap about Keroro, and how hard he is to deal with. However, Keroro's subordinates are found as Natsumi seems very displeased and confused, Fuyuki is shown to be confused as well. And to top it off an alien girl named Angol Mois appears to have joined up with the Keroro Platoon.
Later Keroro is seen talking with Giroro about the invasion of Pekopon, Giroro commenting on Keroro not even doing one thing. Keroro is about to object when a letter flies into his forehead. It is revealed to be a hologram of Viper as he says that he has kidnapped Keroro's fellow Pekoponians (Natsumi and Fuyuki) and that if he wants them back he has to come to Viper's location. Keroro immediately gathers up his Platoon, as they head off to fight Viper. Viper is than shown with Natsumi and Fuyuki, the latter tied up. Natsumi is shown trying to bargain her way out, but to no avail. However, the Keroro Platoon appear and do an attack called Keroro Platoon One-Hit Kill, Viper is soon knocked out, as the Keroro Platoon celebrate their victory, and decided to continue the invasion. Fuyuki notes on how hard it's now going to be now, as Natsumi says that they should go through the original rescue plan.
Note: The File is mainly focused on Episode 13, so the differences noted will be about that episode,
- In the original it was Koyuki Azumaya and Dororo tied up.
- Keroro has the kidnapping during the day, while in the original it was at night.
- In the original the Platoon wear capes during there announcement to do the Keroro Platoon Deathblow.
- Even though Mois made her debut in this series, she is playing a cameo.
- Momoka made a cameo appearance in this episode, but this doesn't count as her debut.
- The episode is mainly a tribute to the thirteenth episode in Season One, but also references episode 2, episode 3 and episode 9.
- The letter that landed into Keroro's forehead was a running gag in the original where most important letters ended up embedded into Keroro's body.
- During the scene where Mois did a backflip, her panties could be seen.
- During the scene where Keroro rescues Tamama, Momoka is shown wearing her Kissho Academy school uniform in which marks the only time the Kissho Academy's school uniform is presented in flash anime.
- Giroro's scar and belt change direction five times.
- Kururu's spirals on his glasses change directions five times.
- Tamama's symbol changes directions 5 times.
- When the Keroro Platoon was going to perform the attack on Viper, Kururu's mouth is missing his teeth. He has the same mouth like Keroro and Giroro.
- When getting ready to perform the attack on Viper, Keroro, Tamama, and Giroro's symbols on their bodies are swapped for a brief second.