Kirawaremono no Akuyaku Reisoku ni Tensei shita noni, Nazeka Mawari ga Houtteoite Kurenai

"I," a salaryman in modern Japan, suddenly find myself reincarnated into a video game world... as Klaus Müller, the ugly, villainous son destined to be the butt of the plot!! Realizing that following the original game's plot will lead to his condemnation and execution by the hero, he begins to take action to avoid his disastrous ending. Through hard work, Klaus earns the trust of those around him, including the heroine and his family. But then, unintentionally, he achieves great success and attracts a lot of attention...!? The epic fantasy of a scumbag's triumphant return begins now!!

(Source: AlphaPolis, translated)