Koro's Father is a supporting character in the anime Mushi-Shi, primarily featured in the episode "Raindrops and Rainbows." By profession he was a carpenter, but his most defining trait is an all-consuming obsession with rainbows. This fixation eventually led him to abandon his work and his family, leaving behind his duties to chase the elusive phenomenon. His motivations are driven by a deep fascination with rainbows, which he sought not only to see but to understand and capture. This same obsession was passed down to his son, Koro, who inherits his father's compulsion and sets out on his own quest to grasp a rainbow. In the story, Koro's Father functions as the origin of his son's journey, influencing Koro's actions through the legacy of his single-minded devotion. His key relationship is with his son, whom he shapes through the inheritance of his passion. The character does not undergo further development; he is depicted as a figure defined entirely by his pursuit. He possesses no special abilities beyond an intense determination that overshadows all other aspects of his life. His role is indirect, serving as the catalyst for the central conflict of the episode.