https://www.dlsite.com/books/work/=/product_id/BJ724523.html
https://www.dlsite.com/books/work/=/product_id/BJ01227575.html (English)
https://coolmic.me/titles/2979 (English)
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Forced to Have Sex For a Week— Teased and Forced to Come by My Piece of Trash Childhood Friend

"I'm gonna come again… I'm gonna c-…" Mika Oyamada was drinking away her sorrows because her boyfriend who she'd been dating for a year and a half had cheated on her. Her younger childhood friend, Mahiro Otake, watched over her as she drank too much.
He said, "You must be exhausted after all you've been through," and had her lay down and started giving her a massage. Since she trusted Mahiro after knowing him for so long, she entrusted her body to him without any worries. It was a relaxing massage at first, but Mahiro's hands gradually began to touch her sensitive areas.
At first, she thought it was just her imagination, but his hands began to touch her private parts… "You're wet, Mika." With those words as a cue, Mahiro's fingers began to forcefully knead beneath Mika's underwear.
Mika was forced to come because of the pleasure, but…!?