https://www.dlsite.com/comic/work/=/product_id/BJ01321920.html

(成年コミック) [プレステージ出版(森乃こあら)] 胸いっぱいに恋して1 [DL版]

Base +10, akaokutan +11

[Synopsis]
Yuuki had two childhood friends.
They were 'pure' and pretty twin girls.
They got along well because their houses were next to each other but when they went to college, they suddenly changed...
Yes, they became flashy, chubby, big-breasted gals with pierced ears...
They had changed so much that Yuuki became estranged from them and entered his third winter of school life.
But one day, when Yuuki returned to his room...
<Welcome back!>
One of the twin sisters, Aina, was waiting for him in his room.
Aina said she had something to ask Yuuki. What she wanted was...
<Have sex with Aina.>
<Stop, stop!>
Aina had always had a way of thinking that was hard to understand.
It seems that it hasn't changed even now.
Maybe it's just her appearance that has changed...
When I asked her why she suddenly started talking about sex, she said that she didn't want to graduate without having any memories of her school life.
<It doesn't have to be me then.>
<Only Yuuki can do this and since you're my childhood friend, I can feel at ease>
Before he could stop her, Aina changed into her underwear and showed off her plump body.
And then, her childhood friend, now a gal, seduces Yuuki...!
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Can't wait for the sequel with the other twin sister and seeing them having a threesome (͠≖ ͜ʖ͠≖)

Base +22, akaokutan +11, Hotsea1212 +6

加个完全修正的tag吧

Base +7