https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_567981/

Part 1
Raw: https://e-hentai.org/g/3368112/3b421c4dde/
Chinese (MotherEmperor): https://e-hentai.org/g/3156198/bd9bc17abd/

Part 2
Raw: https://e-hentai.org/g/3201382/faba30e1ae/
Chinese (巨乳幻想): https://e-hentai.org/g/3250818/db08fc820b/
Chinese (MotherEmperor): https://e-hentai.org/g/3292027/d4495a5a43/

[Synopsis]

Ayumu, Himari, Tsumugi and Nagisa are a group of four childhood friends who have always done everything together.
Going to school, studying, playing, traveling, dating... and even sex.
It was normal for the four of them to always have sex together but during the summer vacation of their university years, one of the childhood friends, Nagisa, makes a suggestion.
"Don't you want more time to be alone with Ayumu?"
From that suggestion, Ayumu will spend a "one-week lovers' period" with each of his three childhood friends...

The third week of his lovers' period will be spent with his dark-skinned childhood friend, Nagisa!
Although she likes sex, Nagisa Aya says she is not as into Ayumi as the other two and on the first day of their relationship, she makes a proposal.
"What I want to say is...tell me how much you like me...during this time we're together."
It was a proposal to test Ayumi's feelings for her by living together for a week.
From then on, the two of them do their own "lover-like acts" through their cohabitation and Ayumu conveys his feelings for Nagisa...and on the last day of their relationship, the two of them have plenty of time throughout the day...

Base +28, SoraXR +7, nuts987 +13

这个系列还有两部啊，真好真好。这么量大的全员青梅竹马后宫真的很少了。

Base +8