Kusuo has an average build and height, short hot-pink hair, fair skin, and pale purple eyes with no visible pupils or emotion. He wears white psychic limiters on either side of his head, resembling cyan antennae with pink, lollipop-like spheres. He also wears white glasses with lime-green lenses to prevent his petrification ability. At school, he wears the standard male PK Academy uniform. Outside school, he sometimes wears clothes sewn by his mother, though her eccentric taste often forces him to buy his own clothes. Kusuo can transform into any living being, although transformations have a two-hour interval. His female form is called Kuriko, with lighter pink hair, clear glasses, and the female PK Academy uniform. His cat form is called Psi/Sai and has white fur, glasses, and a limiter worn as a collar. As a child, he did not use limiters or glasses and was much more openly emotional, mischievous, and cheerful. However, constantly hiding his psychic abilities and having them interfere with his life caused him to become increasingly withdrawn. In the present, Kusuo is reticent, self-centered, reclusive, and strongly dislikes being the centre of attention. He rarely speaks aloud, preferring to communicate telepathically. He often avoids social interaction and tries to make people lose interest in him. Despite this, he is extremely perceptive and good at understanding what people want and quietly helping them achieve it. Kusuo is genuinely kind-hearted and surprisingly selfless. He is willing to sacrifice his own happiness for others and frequently helps people without expecting anything in return. He hates burdening others, owing favours, or relying on people. He is responsible, helps around the house, saves money despite being able to obtain things through his powers, protects others' privacy and wellbeing, and deliberately avoids using his psychic abilities when he wants to accomplish something himself. Because of his reserved nature combined with his kindness, those close to him often consider him a tsundere. Although intelligent and powerful, Kusuo has some flaws. He can lack common sense, especially regarding social boundaries and the internet, and can be manipulated easily by sweets. He is prideful about his abilities, stubborn, somewhat pessimistic, and occasionally nosy when he thinks he can help someone. He is also a good listener and can admit when he is wrong. Over time, despite initially wanting absolutely no friends, he becomes attached to and protective of his classmates and eventually considers several of them genuine friends. Kusuo dislikes most social activities and usually spends his free time alone. He is a bookworm who often visits the school library and enjoys television, anime, and movies. He is frightened of bugs and Riki Nendou because he cannot read either of their minds. He has an extreme sweet tooth, with coffee jelly being his favourite food, and can be easily tempted by it. Kusuo rarely uses his actual voice and almost always communicates through telepathy. He has only spoken aloud a handful of times. He is ambidextrous, though he tends to use his left hand when comfortable or around people who know about his powers and his right hand when trying to blend in. His attendance number is #7. His deep pink hair is the complementary colour of PK Academy's teal uniform. Kusuo has repeatedly reset the Earth and has consequently repeated his second year of high school six times. Despite claiming he does not believe he will fall in love, he is highly observant of romantic relationships and often interferes to help others. Aiura Mikoto has also predicted that she and Kusuo are soulmates. Overall, Kusuo is quiet, sarcastic, emotionally restrained, intelligent, stubborn, and easily irritated by other people's antics. Beneath his detached exterior, however, he is deeply caring and protective of the people he has grown close to.