Shitamachi Rocket.

Tsukuda Kohei was once a researcher with the Aerospace and Science Exploration Agency and now runs Tsukuda Industries, a small factory which was left by his father. Although his relationship with his teenage daughter Rina is somewhat strained, business at Tsukuda Industries has gradually started to improve. But Tsukuda puts too much effort into his dream of developing a rocket engine and business declines little by little. One day, a major client suddenly declares that it is dropping Tsukuda Industries. Then, Tsukuda Industries gets sued by a big rival company, Nakashima Industries, for patent infringement. Tsukuda Industries’ reputation is hurt and financing from banks is also in a desperate situation. In the midst of this, Teikoku Heavy Industries, one of Japan’s leading corporations, offers to buy a patent which Tsukuda Industries possesses for 2 billion yen