Neo Kyoto is a place where everything is decided through the card game "Build Divide." From resolving personal conflicts to determining social status, success in Build Divide means success in life. The biggest ambition of every player is to become the King, whose peerless skills grant them near-total rule over the city.

One day, a young man wakes up in Neo Kyoto—with the knowledge of just his name, Teruto Kurabe, and carrying only a deck for a card game he no longer knows. Teruto soon encounters another player, Sakura Banka, who helps him remember both how to play Build Divide and his original mission: that no matter what, he must meet the King. Teaming up together, Teruto and Sakura find that their best chance for a royal audience is with the Rebuild tournament, where the one who collects twenty-one tokens from other competitors can challenge the King for their throne. However, as Teruto continues to play, he begins to regain his lost memories that call into question the very nature of Neo Kyoto.