He originally believes that the key to the Junction Point is the elder Yuto Sakurai, traveling back in time to January 10, 2007, to kill him. However, when the changes to the timeline from Sakurai's death are undone, he believes that Den-O is the culprit, and sends the Imagin Ryutaros to the DenLiner with a permanent ticket with the charge of killing Ryotaro. When Ryutaros refuses to follow through with his mission, Kai reveals himself and tries to get Ryutaros to sabotage the ZeroLiner, taking the DenLiner and Den-O Belt out of commission. After this fails, he notices that Yuto does not protect his future self from harm in the past, but rather protects Ryotaro.