Enkou JK Bitch Gal - Oji-san to Nama Pako Seikatsu

Based on the erotic game by ZION.
Takeshi is a middle-aged businessman who has moved to Tokyo for work. One night, two high school girls, Ami and Nana, approach him for compensated dating, and he ends up having physical relations with them. Attracted by Takeshi's wealth and energetic sex, Ami and the others continue to have sex with him, teaching their young bodies the pleasures of being with a grown man. Through compensated dating, Takeshi meets a variety of unique girls, and his life as a solo worker is filled with the pleasures of youth!!
(Source: Parabook, translated)