Tadashi Ore wa Heroine Toshite

After the manufacturing company of R-18 dating sims undergoes dissolution, an obsessed 30-year-old virgin visits a deserted shrine and requests to be sent to the world of their masterpiece, Kokorone Heartful.
Although his wish is granted, the god mistakenly turns him into the heroine instead of the protagonist. Ordinarily the romancing choices are left to the protagonist. However, unless he completes the game as the heroine, he will be forced to remain in Kokorone Heartful as a woman forever.