Keiichiro Koibuchi hails from the wealthy and influential Koibuchi political family. Tall and physically attractive, he possesses a naturally charming demeanor. Despite his privileged background and success as a businessman, he exhibits a compassionate and caring nature, frequently helping those in need without expecting anything in return. His life changes significantly when he encounters the residents of Amamizukan, an apartment complex housing a group of socially isolated female otakus known as the "Sisterhood" or "Nuns." While not sharing their specific obsessive hobbies, he becomes deeply fascinated by their intense passion and dedication. He develops a particular interest in Tsukimi Kurashita, the socially struggling protagonist, becoming her primary source of emotional support. He offers genuine understanding and actively assists the entire group in navigating various personal and professional challenges. A central conflict arises from redevelopment plans threatening the Amamizukan neighborhood, involving demolition for commercial projects. Recognizing the vital importance of preserving the residents' home and way of life, he leverages his family's substantial financial resources and social influence. His intervention proves instrumental in thwarting the eviction plans and safeguarding Amamizukan. His personality reflects ESTP traits: confident and outgoing interactions, a strong ability to adapt quickly, and a pragmatic, solution-oriented approach to problems. He is highly observant of his surroundings, effectively using this awareness in both business and personal contexts. However, this can sometimes manifest as perceived insensitivity or difficulty with emotionally charged situations or abstract concepts. He further aligns with Enneagram Type 8, "The Challenger," evidenced by his strong will, assertive communication, and distinct need to maintain control. He is unafraid to voice opinions and often takes charge to achieve outcomes. While valuing power and engaging in confrontation, he also possesses a protective instinct towards those he cares about. His character embodies the archetype of a modern-day prince charming, combining wealth, accomplishment, and a fundamentally kind nature. His actions consistently demonstrate a depth beyond superficial charm, highlighting a genuine desire to assist others meaningfully.