Kaito's elementary classmate who calls him Umi-chan and has feelings for him. Kaori first appears in episode 6 on a trip to the beach with her friend Chiharu Arisawa to forget the fact she was dumped. She runs into Kaito and the rest of his group, who also end up being at the same place as her. The sight of Kaito brings back past feelings she had for him and causes her to confess her feelings of affection towards Kaito. She is later rejected by him, by which the words he said reminded her of the way her boyfriend dumped her, which makes her cry.