Full name: Senku Ishigami. His catchphrases include "Exhilarating" and "ASAP," and he frequently uses the phrase "ten billion" as a modifier. On rare occasions, he even says "ten billion percent." He has an arrogant and audacious personality, basically never using polite speech with anyone. He always wears a fearless smirk, laughing with a characteristic "Ku-ku-ku" while mixing in sarcasm. He has a foul mouth and often mocks people, but he never ridicules a person's hard work.

She ends her sentences with "-nandayo" (it's just how it is). For example, "Suika is being helpful-nandayo!" or "I don't really understand-nandayo."

Full name: Ryusui Nanami. First person: I (boisterous, confident). A magnanimous and highly charismatic man with a bold, open-hearted personality. He is very expressive with his emotions, but he is also incredibly composed; he has never truly been enraged. He is not obsessed with his position as a leader; if it is to get what he wants, he has no qualms about working up a sweat himself. He listens carefully to others' opinions, explains the logic behind his choices, and dislikes suppressing the will of others to move them. While he is confident, he is never self-righteous. According to Francois, this is due to his personal aesthetic: "He doesn't want to be the only one shining; he wants to make others shine and then desire even that." His catchphrase is "I want it!". When asking a question, he ends with "Am I wrong?". For example, "Science is just steadily driving in wedges. Am I wrong?"

First person: I (formal, polite). A butler-chef who has been at Ryusui Nanami's side since before the petrification. They have elegant manners and address everyone, including the young Suika, with the honorific "-sama." Possessing diverse skills such as English, French, housekeeping, and babysitting, they opened a restaurant and enriched the diet of the Kingdom of Science. Ryusui, who hit it off with Senku over their shared difficulty with the food situation, negotiated with a fungus that held the last of the revival fluid to revive Francois specifically for their skills. A specialist with an aesthetic of hospitality, they never say "I cannot do it," but they also do not try to handle everything alone; they carefully prepare and cooperate with the person best suited for the situation to fulfill a request. This is a trait they share with Ryusui. Calm and collected, they never show fatigue or emotion, but they are the one who understands Ryusui's "desire"—which led to his isolation in the Nanami family for acting honestly on his whims—evaluating it as "Desire is justice." They deeply respect and love Ryusui.

Full name: Tsukasa Shishio. He has reconciled with Senku and the others and is now part of the Kingdom of Science.

He has reconciled with Senku and the others and is now part of the Kingdom of Science.

He has reconciled with Senku and the others and is now part of the Kingdom of Science.

Full name: Stanley Snyder. He has reconciled with Senku and the others and is now part of the Kingdom of Science.