ギャルゲーのチート主人公だったはずなのに、転生してきたモブにヒロイン全員を寝取られ全てを失ってしまったので、最悪の悪役になって復讐します (Associated Names)

An inconspicuous boy who ends up being a background character no matter where he goes, everything about him is ordinary. He hated that about himself and did everything possible to “become the protagonist one day!” He worked hard on studying, sports, grooming… However, in the end, none of his efforts were rewarded, and he tragically…