Kōji Amami is the owner of the cafe Rainy Color, a role that makes him a central yet often enigmatic figure in the series. His personality is defined by a sense of mystery and a love for travel and exploration, which leads him to frequently journey to various places and bring back souvenirs that he displays in the cafe. This adventurous spirit drives his primary motivation in Rainy Cocoa in Hawaii: the decision to open a new branch of Rainy Color in Hawaii. In the story, he acts as the catalyst for the third season's events by selecting Nozomu Tokura to serve as the manager of the new Hawaiian location, thereby placing Nozomu in a challenging new environment. His key relationships include his interactions with Nozomu, whom he entrusts with the responsibility, as well as with other regular characters such as Shion Koga and the cafe's staff. While his development across the series is limited, his consistent role as the owner who sets major plot points in motion underscores his importance. Notable abilities include his knack for unconventional ideas and his willingness to take risks in expanding the cafe's reach, though no extraordinary talents are highlighted. Overall, Kōji Amami remains a quietly influential presence whose actions shape the direction of the narrative.