Bishoujo-ka shita Ojisan dakedo, Gachikoi sarete Komattemasu I'm a Pretty Girl-ized Ojisan, but I'm in Trouble for Being Seriously Loved.

Synopsis

All that awaits former middle-aged men who get full of themselves after turning into pretty girls is a bad time?! It's up to you decide whether it's just desserts or a happy ending! (Source: Kadokawa, translated)