Igarashi Natsu [TRUSTED]

Igarashi Natsu is the soul of Dr. STONE ’s second half. He is the reminder that beneath the blueprints and the chemical reactions, science is a human story. It is the story of children waiting for their parents, of communities preserving stories, and of frightened young men finding the courage to face the cosmos not because they are unafraid, but because they love. In a series that often celebrates the cold logic of the laboratory, Natsu stands as a warm, beating heart—proof that the most essential element for rebuilding civilization is not just intelligence, but empathy. He is, without question, the most human character in a world of stone.

His knowledge of the American colony, the abandoned space center, and the legends of the “Golds and Silvers” (the petrified astronauts) is invaluable. Without Natsu’s patient guidance and his community’s preserved stories, the Kingdom of Science would have wandered blind. In this sense, Natsu embodies the theme that science is not just about formulas and beakers; it is about history . You cannot build the future if you do not remember the past. Natsu’s tears upon seeing the real Soyuz rocket are not just personal grief; they are the grief of an entire world realizing that the gods of the old age were merely humans, now frozen in stone. In a series filled with hyper-competent geniuses and superhuman fighters, Natsu’s greatest strength is his emotional vulnerability. He is allowed to be afraid. When the team faces the dangers of the New World—the hostile Stanley Snyder, the treacherous terrain, the looming threat of Why-Man—Natsu does not hide his terror. But he acts anyway.

This is a crucial narrative lesson. Senku’s courage is born of certainty and knowledge. Kohaku’s courage is born of physical prowess and instinct. Natsu’s courage is born of love . He fights not because he knows he will win, but because he cannot bear to live in a world where he did not try to save his family. His decision to board the Soyuz capsule during the final launch preparations—not as a commander, but as a son sending his parents a message—is one of the most quietly heroic moments in the series. He proves that emotional strength is as vital as physical or intellectual strength. By the end of the series, Igarashi Natsu does not become a famous scientist or a legendary warrior. He remains a farmer, a guardian, and a man of deep feeling. But his role is foundational. He represents the purpose of the Kingdom of Science. All of Senku’s rockets and revival fluids are ultimately meaningless if there is no one to care about the people being saved. Natsu is the emotional core that prevents the series from becoming a cold, procedural textbook.

In the grand tapestry of Dr. STONE , a manga and anime series that glorifies human ingenuity and the relentless march of science, it is easy to be dazzled by the pyrotechnics of Senku Ishigami’s intellect or the raw power of Tsukasa Shishio. Yet, woven into the fabric of the series’ second major arc—the “Age of Exploration” and the journey to the other side of the petrified world—is a character of quiet but profound importance: Igarashi Natsu. Often affectionately called “Soyuz” by fans (a reference to his ersatz role as a Soyuz spacecraft commander), Natsu is more than just a brawny crew member. He is the living conscience of the new stone world, a bridge between the primal fear of the unknown and the scientific courage required to face it. The Heir to a Burden: Introducing Natsu When the crew of the Perseus first encounters Natsu on the shores of North America, he is presented as a dichotomy. He is physically imposing—a son of the formidable warrior Kohaku—yet his demeanor is gentle, uncertain, and deeply melancholic. He is not the brash, confident fighter one might expect from the Ishigami Village bloodline. Instead, Natsu carries the weight of a broken promise and a lost past.