The season changes to winter. Makoto makes a decision in order to greet the spring that is waiting beyond.

After realizing the value of life and the importance of his own allies, Makoto finally got his smile back. As spring turns into summer, he finds himself learning more about those comrades and getting closer to them. He even meets new friends, including Aegis, an anti-Shadow android, Ken, a grade-schooler who seeks to get revenge for his late mother, and Koromaru, a dog who can use a Persona. Makoto wishes that everything will continue just as they are. However, little by little, the pieces and people in Makoto's new, happy life begin to fall apart, and he is forced to suffer the loss that comes with it.

Tai is now a university student, living alone, working hard at school, and working every day, but with his future still undecided. Meanwhile, Matt and others continue to work on Digimon incidents and activities that help people with their partner Digimon. When an unprecedented phenomenon occurs, the DigiDestined discover that when they grow up, their relationship with their partner Digimon will come closer to an end. As a countdown timer activates on the Digivice, they realize that the more they fight with their partner Digimon, the faster their bond breaks. Will they fight for others and lose their partner? The time to choose and decide is approaching fast. There is a short time before “chosen children” will become adults. This is the last adventure of Tai and Agumon.