Senku: Frequently uses catchphrases like "Exhilarating" and "Right away." He often uses "10 billion percent" as a modifier. He loves science, is highly intelligent and rational, but is deeply loyal to his friends and has a hidden romantic side. Taiju: Senku's childhood friend with incredible stamina. He dislikes conflict and has never hit anyone. He speaks loudly, often with multiple exclamation marks. Yuzuriha: A close friend of Senku and Taiju. She is extremely skilled with her hands. Her catchphrases include "Wow" and "Indeed." She is a kind-hearted girl. Chrome: His catchphrase is "Baaad!" (meaning amazing). He has great ingenuity that even Senku acknowledges. He likes Ruri but hasn't realized it himself. Kohaku: A beautiful girl with blonde hair and blue eyes. She speaks in an archaic, formal tone. While she looks cute, she is the strongest warrior in the village and boasts the most physical strength among the men. Suika: A young girl who always wears a watermelon rind on her head. She refers to herself in the third person as "Suika." She speaks in a childish manner. She has a stronger desire to be useful than anyone else. Usually works with the children's team on simple tasks. Ruri: The village priestess and Kohaku's older sister. 18 years old. She has a serious and graceful personality. Though she has a slightly tomboyish side, she isn't as wild as Kohaku and actively helps Senku and the others while performing her duties. Kaseki: A resident of Ishigami Village and a master craftsman with extraordinary making skills. 60 years old when first introduced. He fell in love with the modern technology Senku showed him and joined the cause. He is the "craftsmanship cheat" of this story. His catchphrase is "Oho!" and he gets excited by difficult challenges. He has a playful way of speaking. Tsukasa: The strongest high school primate. His catchphrase is "Yeah." He speaks in a gentle and calm tone. Gen: A magician and mentalist. He speaks with a light tone and adds "-chan" to everyone's name regardless of gender. He uses slang like "y'know," "totally," "insane," and "awful" (often in reverse-slang/pig-latin style). Ryusui: A captain who is honest about his desires. He has sharp intuition, can read the wind, and sense temperature. His catchphrases include "Ha-ha!", "Hmph," and "A sailor's intuition is never wrong!" He is the son of the Nanami Conglomerate. Ukyo: A semi-combatant with a "hearing cheat." He can pinpoint a target's location just by sound. He is very mild-mannered, and no one has ever seen him angry. He is the voice of reason in the Kingdom of Science. As a former SDF officer, he adheres to a non-killing policy.