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.

The year 2015 CE. The last era in which magecraft still thrived. The Chaldea Security Organization was founded to focus on preserving the continuation of human history. They observe a world which magecraft couldn’t observe and science couldn’t measure all to prevent the certain extinction of humanity. But one day, the future that Chaldea continued to observe disappears and humanity’s extinction in 2017 becomes clear. Rather, it had already happened. The cause seems to be related to Fuyuki, a provincial town in Japan, in the year 2004 CE. There, an “unobservable region” that had not existed before appears. Based on the assumption that Fuyuki is the reason for humanity’s extinction, Chaldea issues an order to explore, investigate, and possibly destroy this singularity – a quest for the Holy Grail, the Grand Order.