Kaito is an energetic person with a passionate heart, who lives for dreams and romance, and tends to give somewhat dramatic encouraging speeches for others. He believes you need to take risks for the sake of your dreams and should't limit yourself nor ever give up. Due to his clichéd hot-blooded spirit and his document falsification he could pass the astronaut examination, proving that he is smart. Being the Ultimate Astronaut, he harbors a dream and a great longing to go to space, and already considers himself a space legend. He often refers to himself as "The Luminary of the Stars" and talks about the Universe being on his side.

Throughout the game, Kaito described himself as a passionate protagonist of his own story who would help the others to survive the killing game. He considers himself a hero type, and occasionally offers to make other people his "sidekicks". Because of that, Kaito always tries his best to unite the group, and he is very much a reliable older brother type of character. He is very loyal to his friends and always there in order to aid them, such as when Shuichi Saihara broke down after Kaede Akamatsu's death. He offered his help to regain his spirit by starting training routine during the nighttime and even made him his "sidekick". It is also because of this nature that he became a moral support to the other participants. According to Shuichi, Kaito has the ability to draw people to him, and he has been described as an interesting and amusing person.[4]

Interestingly, Kaito seems to be a good judge of character and can give correct advice at times. While he is seen helping Shuichi and Maki in the main story, this is even more notable in the bonus mode Ultimate Talent Development Plan, as he correctly judges multiple other charactersーfor example, he tells Izuru Kamukura that he will begin to think everything is boring if he keeps repeating how boring everything is, he quickly notices that Nagito Komaeda isn't truly interested in him nor space (as he only cares about him as a symbol of hope) and he tells Mondo Owada you can't move forward in life if you keep looking at past. However, Kaito is also shown to be easily angered by mindsets that contrast his own, and he stubbornly refuses to believe in them. Notably, he hates Kokichi's lies and unwillingness to cooperate. He also cannot empathize with Ryoma's suicidal way of thinking, considering him a sissy and a fool, as he believes there is always a reason to live even if just small things like good food or friends. He is also notably hot-headed in general, occasionally taking action without thinking and wanting to punch others if angered enough.

Undoubtedly, his biggest flaw is his arbitrary complete trust in others, which is often misguided. He is sincere and believes in friendship no matter what, trusting who he wants to trust even against all evidence and logic. He believes Maki without questions despite evidences against her, with his only reason being "an official hunch from Kaito Momota, the Luminary of the Stars himself", causing other students to call him an idiot because of it. He hates to be called an idiot, claiming that it hurts his feelings. During the fourth trial, he denied all the clear evidence that showed Gonta Gokuhara is the killer of Miu Iruma, which ended up making things worse.