A World Where Only I Can Use S*x-Based Payment App, also known as 俺だけセックス決済型電子マネー【Hcy（エチィ）】が使える世界, is a captivating Japanese web novel that delves into the adult, ecchi, and school life genres. The story revolves around a male protagonist who navigates a world where he has exclusive access to a unique payment app. With themes of brother complex, cheats, childhood friends, and incest, this novel offers a compelling narrative that keeps readers engaged with its intriguing plot twists and character dynamics.