Kaito Umi is an outgoing, cheerful, and lively person. She is sociable and can express her feelings frankly. Once she starts talking about something she likes, she becomes very talkative. She respects others' hobbies and dislikes people who casually insult others' interests. She has strong actionability and immediately puts her ideas into practice as soon as she has them. She is extremely fond of cosplay and often dresses up as female characters from animations, games and comics, believing that cosplay is the ultimate expression of love for a character. Besides, she also enjoys eating all kinds of Japanese cuisine.