Build Divide: Code Black

One day, Teruto Kurabe is wandering around the city with a piece of bread in his hand, and discovers a girl named Sakura Banka who is being attacked by a thug, so he uses the power of a mysterious card in his possession to save her. Witnessing his powers, Sakura speculates that Teruto must be highly skilled in Build-Divide and requests a battle with him. She has been searching for a powerful player that could help her win through the Rebuild Battles, which would allow her to challenge the King. However, Teruto has lost all his memories…

Teruto reluctantly accepts Sakura's offer to take part in Rebuild Battles. While they are walking in the city together, she realizes that Teruto is wearing a uniform from Komoku Academy, which is the same school she is a student of. For some reason, one of the only things that Teruto remembers is his strong desire to battle the King. They search the school grounds to find other Build-Divide players, but a second-year middle school student named Hiyori Munenashi suddenly appears before them and…

Hiyori pleads to become Teruto's disciple, and follows Teruto and Sakura around. In order to obtain more chips, Teruto and the crew head to a place which is rumored to be where Build-Divide players gather. However, before they arrive at the location, they discover that someone has already defeated all of the players, so they are forced to search in another area. 

Teruto starts "training" Hiyori by going to various bakeries in the city. They decide to go after a special croissant, but are attacked by a mysterious girl. Meanwhile, Sakura looks for a challenger for them, but feels she's being somehow deceived.

Teruto is down after his fight with Kikka and looks like he's given up on the fight against the King. While Teruto decides to go fishing, Sakura and Hiyoko go out for cake, with the idea of coming up with a plan to get him to regain his spirits.

Teruto finds Naomitsu unconscious in front of his tent. Along with Sakura and Hiyoko, they discover that he was attacked by a group commanded by Prof. Dairo Keisen, known as a teacher of cards. So they decide to go to his lab to find out more details.

Teruto, Sakura and Hiyoko go to a resort with an artificial beach. While enjoying the opportunity to relax and forgetting about the battles, Sakura becomes tormented by a girl. When the girl's identity is finally revealed, a battle ensues!

Teruto starts visiting places from his past and starts to remember his past with Kikka. Having an idea of the places the two frequented, Teruto begins to remember what made the two distance themselves.

Teruto is close to getting the key chips needed to face the King. And he does everything to get it. However, in his path appears Mikhail, who is also a key chip away from forming the key. Will Teruto be able to beat him?

Sakura tricked Teruto and his friends and decided to face Kikka, the king, alone. The battle however is very risky and could mean your end. Meanwhile, Teruto tries to find a way to get to her to help her in this battle.

Teruto begins his battle with Kikka. Meanwhile, we see memories of when Teruto defeated the king earlier and what the world of Neo Kyoto is all about.

Teruto's battle against Kikka continues, but will he be able to win? Teruto has reached the end of his path, but will he be able to save the people he cares about?