Sōichirō Amano, born into poverty in 1965, ascended through relentless effort to become a wealthy hotel magnate with multiple mansions and vacation homes. A graduate of the elite Meguro River Academy, he cultivated his empire via sharp business acumen. His calm, enigmatic demeanor cloaks a calculating mind, adept at sidestepping direct questions and obscuring his motives—highlighted by his cryptic remark to Nagi: “Even if you marry your little sister Sachi, things will turn out fine.” After uncovering Nagi and Erika’s accidental birth switch, he strategically housed them together to nurture their bond, reflecting his preference for indirect manipulation over coercion. Though orchestrating their proximity, he avoids pressuring them, maintaining an aloof dynamic. Nagi grapples with connecting to his inscrutable biological father, while Erika, his adoptive daughter, voices unease around him despite his paternal role. His opulent lifestyle starkly contrasts the Uminos’ modest restaurant livelihood, yet his wealth allows effortless manipulation of circumstances, from securing housing to shifting family dynamics. While seemingly invested in both children, his ambiguous communication fosters emotional distance, leaving others questioning his true intentions. This strategic precision extends to business, where he excels in negotiation and long-term planning. Across all narratives, he remains a shadowy catalyst, his enigmatic influence persistently driving pivotal familial and romantic tensions behind the scenes.