Mysteriously transformed into mini versions of themselves, Goku and his friends travel to the Demon Realm to uncover the truth and find a cure.

It is the Taisho Period in Japan. Tanjiro, a kindhearted boy who sells charcoal for a living, finds his family slaughtered by a demon. To make matters worse, his younger sister Nezuko, the sole survivor, has been transformed into a demon herself. Though devastated by this grim reality, Tanjiro resolves to become a “demon slayer” so that he can turn his sister back into a human, and kill the demon that massacred his family.

Rich heiress Reiko Hosho lives a double life as a novice detective, fighting crime under Inspector Kazamatsuri—also from a wealthy family. After work, Reiko sheds her pantsuit to don a lovely dress for dinner each day. Difficult cases force her to confide in her butler Kageyama, who proceeds to savagely ridicule her inability to solve mysteries, all while brilliantly unraveling each case himself.

High school freshman Hiro Amanokawa activates a mysterious device left behind by his father called a "Digivice" that makes unknown creatures that cannot be seen by ordinary people, the Digimon, visible to his eyes. This is the story of this other side of the world that nobody is aware of. With their friends, Hiro and Gammamon dive into the mysterious world where these creatures live.