At DATS Touma is greeted by Masaru and Agumon who say they have been waiting for them. Agumon holds out a drink and Masaru tells Touma to have a warm seat. Touma asks what is going on and Masaru tells him he has to make up an exam at school. Touma thinks Masaru wants him to help him study but Masaru says he needs Touma to take care of Chika on her birthday and show her a good time until he is done with the test. Touma says Yoshino should do it but Masaru says it needs to be someone who can act like a father.

Later that evening Touma comes over to Masaru’s house and introduces himself to Masaru’s family. At first he is reluctant to agree to watch over Chika but when Sayuri appears he changes his mind. Chika asks Touma if he has a partner Digimon and he shows her Gaomon. Touma and Gaomon are invited to dinner and they reluctantly accept. At dinner Touma notices a picture of Masaru’s family and leaves early. (He kind of has a thing about the whole concept of family.) As Touma leaves, he tells Masaru that he will watch over Chika tomorrow.

At his house, Touma organizes a schedule so that he can give Chika a great birthday.

It is now the day of Chika’s birthday and Touma shows up with flowers for Chika and Sayuri which shocks Masaru. Masaru heads off to take his make-up exam and Touma says they should head off. However, Chika wants to go somewhere specific which ruins Touma’s plan.

They arrive at a video arcade and Touma wins Chika some stuffed animals from a machine. They play some video games together and Touma loses to Chika. He realizes just how related she is to Masaru because he can’t calculate what she will do next. (He didn’t predict her changing his plans or beating him in video games.) They leave for lunch at a French restaurant but Chika says there is somewhere else she would like to eat.

The three go to a mojayaki restaurant and Touma is surprised when he enjoys the meal. He tries to pay with a “Toei” credit card but the restaurant only accepts cash so Sayuri is forced to pay which puts a damper on Touma’s mood. They leave the restaurant and Chika says she wants to see some fireworks.

Touma takes them to a theme park and says the fireworks will appear at night and until then they can enjoy the attractions. Scenes are shown of them enjoying all the rides and it cuts to night where they are on the Ferris wheel. While looking at Sayuri, Touma has a brief flashback of his mother. Loud bangs and flashes are then seen and Touma realizes it is a Digimon called BomberNanimon. Touma jumps out of the Ferris wheel and confronts the Digimon with Gaomon. He reports the Digimon to DATS and is told to stand by while help arrives but he says it is personal. Gaomon digivolves into Gaogamon.

Gaogamon and BomberNanimon begin fighting in the middle of the theme park. BomberNanimon seems to be winning when he pulls out a bunch of bombs but Touma has a flashback of Chika saying she wants to see fireworks. This gives him the idea to have BomberNanimon thrown in the air and destroyed with his bombs. Gaogamon follows his master’s plan and the sky lights up with fireworks which pleases Sayuri, Chika, and the crowds.

Outside of the park Touma appears sadden by the incident and apologizes. Chika tells him it is ok and gives him a kiss on the cheek. Sayuri and Chika say they’re hungry and invite Touma over for dinner.
At Masaru’s house Sayuri, Chika, Yoshino, Masaru, Agumon, Raramon, Gaomon, and Touma enjoy some fried eggs. Masaru and Agumon fight over the last fried egg but Touma swoops in and takes it.