After marrying four sisters, Hiroshi finds himself navigating a complex web of desires and affections. Each wife—Yuri, Saki, Hina, and Miu—brings her own passionate needs, leading to intimate encounters filled with longing and shared ecstasy. Their polyamorous bond deepens through sensual exploration, as Hiroshi strives to satisfy every sister equally, forging a unique and deeply erotic family romance built on mutual devotion and insatiable physical connection.