Yarashikute Kawaii Ore no Rin-chan. ~Rinjin Kouhai-kun no Iki Sugita Shuuchaku ni Hameta to Sareru~

No matter how hard 26-year-old virgin Rin Kagaya works on herself, her dates never seem to end in lasting relationships. In the wake of her latest failed relationship, she heads to work and gets handed a new trainee to look after Yamato Tachibana. He's got stunning looks, flawless style, and a cute personality to boot. The perfect recipe to heal Rin's broken heart. But he has a secret... Now Rin goes home every night and gets herself off to thoughts of her new trainee, but... how did he find out?! As he takes her for himself, his tongue teases her throbbing, sopping loins. His merciless obsession making Rin surrender herself to pleasure. English Translation: Mangaplaza https://www.cmoa.jp/title/304610/