Sakuta's most iconic trait is his consistent deadpan face and manner of speech regardless of his emotional state. He will often voice whatever he has on his mind with a calm demeanor. Sakuta is a socially isolated and calm individual as a result of his ordeal with Puberty Syndrome. While he states that he is not bothered by what people think about him, or care about trying to fit in and be accepted by his classmates, he does admit that rumors about him are sometimes quite painful to hear and that his indifference comes from a feeling that it is pointless to try and go against the "atmosphere"-the social order of school, and tries to hide from it. Nonetheless, he states that he doesn't care if the whole world would hate him, as long as one person would need him, and isn't hesitant about defying social norms.

Despite his anti-social demeanor, he does show care and compassion for those he cares about, especially those who suffer from bullying or the Adolescence Syndrome like his sister and himself.

Sakuta is also not afraid to show his perverted side and will often make blunt and straightforward lewd remarks to the girls he interacts with. However, these comments are mostly jokes he directs at others and is by no means ill-intended.

All in all, Sakuta's personality can be summarized as being incredibly selfless, kind, and helpful, but also very snarky. He's often blunt, honest, and straightforward with Mai, and he enjoys making lewd jokes that leave her flustered. Ultimately, they both love to tease each other, and they have very similar personalities: both are quick-witted, with a sarcastic streak, yet very kind and helpful, with an immensely good heart, and always do what's right.