I'm Just an Ordinary Merchant

Tanizaki Junichiro only just found out that he's the villain, a major one, in an all-Atsushi story. It's set in an alternate world with Chinese elements. The protagonist's father accidentally killed his younger sister, so Tanizaki used his ability to create Naomi and decided to take revenge. He caused all sorts of trouble, then, in a melodramatic twist, fell in love with Atsushi. By the way, the two of them are adoptive father and son. In the end, he smiles as he hugs Atsushi and lets the knife sink deeper, dying by suicide. Tanizaki, with memories of both the original Bungou world and this one: ... They really went all out, huh? To avoid getting stabbed to death, Tanizaki Junichiro, looking deeply aggrieved, sets out to become a swindler. He also raises young Atsushi into a top student. Everyone is curious about their memories of their previous lives, so they go looking for the two of them. Only to discover that Tanizaki Junichiro has become a master swindler. In just a few seconds, he scams them so thoroughly that they have no choice but to work at his shop. Keeping an eye on them is Nakajima Atsushi, wearing glasses and staring solemnly at the Five-Three workbook, while Tanizaki Naomi explains the problems to him with a stream of technical jargon. Everyone: Is something wrong here? Please note: This is mostly a collection of random ideas. Don't be a killjoy, don't be a killjoy. The heartthrob big brother loves nobody. The setting is an alternate world with Chinese elements, but it still has modern conveniences (like phones, Five-Three workbooks, Mori Company, and the Armed Detective Agency). Don't bash anyone, don't bash anyone, don't be a killjoy, don't be a killjoy! Theme: Quiet.