The children of the wealthy go to Shinryou Private Academy. One day, the most beautiful and popular girl at school, Riku Rei, encounters the protagonist of this story, Suigin, who is a poor boy with no family.

The poor student, Suigin, spends most of his days working various part-time jobs, and his only skill is gaming. Suigin meets Riku Rei through an online game. However, since Suigin is playing the game for free, their correspondence is limited.

Suigin finds out that his only way of interacting with Riku Rei is about to end. Suigin ends up in utter shock. However, in the game, Suigin promises Riku Rei to do everything he can to find the flower she is looking for in the game before it ends.

On the last day of services for “Dungeon Century,” many of the players gathered to enjoy some last-minute festivities. Riku Rei waits for Suigin to arrive, but ends up going to find the flower herself because he’s taking so long.

Riku Rei summons Suigin after her father, Riku Yuuki dies, and hands him something that Yuuki apparently left for him. Suigin hesitantly accepts the item: a specialized console to play the new game "Grave Buster."