Character Arc
Kohei Tsukuda is the heart of Shitamachi Rocket, a former rocket engineer who once pursued his dream of building engines before a launch failure and family circumstances led him to take over his late father's small precision-parts factory, Tsukuda Seisaku. As president, he is principled, technically brilliant, and at times stubborn, refusing to compromise on the quality and integrity of his company's work even when the easier path would be to sell out or settle.
Across the first series, Kohei rallies his small workforce to defend the factory's patents and win a contract to supply a critical valve for a domestic rocket engine, treating the project as both a business lifeline and a way to reconnect with the aerospace ambitions he set aside. He balances the weight of payroll and survival against his insistence that craftsmanship and trust come before profit.
In the second series, Kohei extends that philosophy into agricultural machinery and life-saving medical devices, including work tied to an artificial heart valve. He repeatedly clashes with larger corporations and skeptics who doubt that a downtown workshop belongs in such high-stakes arenas, and his arc affirms the dignity of skilled labor and the idea that a small team with conviction can achieve things the giants cannot.
