In post-WWII Japan, Prof. Shikishima has established Shikishima Industries as a technological powerhouse, focusing on robot development. Yet, a dark secret from the war lies at the core of their success, a secret that cost the life of Prof. Kaneda, Prof. Shikishima's mentor. Now, Kaneda's son, Shoutarou, is on the verge of discovering the truth, an event that will alter his life forever.