ほら、そんなに声を漏らすと彼氏にバレちまうぜ？ ～エロゲ世界でモブの少女を寝取ってみた～

The protagonist expresses frustration with the treatment of a sub-heroine, Mitamura Ayaka, in the eroge "Sore tte Happy!", noting discrepancies between her portrayal in promotional materials and her actual storyline. He can't believe Ayaka's character is made to commit suicide after being rejected by the main character, showcasing his preference for her over the main heroine. Suddenly, he feels dizzy and finds himself in an unfamiliar room, wondering if he's somehow entered the world of the game, akin to the plot of trendy isekai light novels.

[Translated from the official site]