Sefure no Senpai

Yuuma (virgin), who is planning to debut in university with a new image, gets to take home Nana-senpai, the unreachable flower from his college club!?

"‘Cause, I'm looking for a friend with benefits right now."

In contrast with Yuuma's bewildered mind, they turn out to have great physical chemistry.

(Source: BookLive, translated)

1-4. Sefure no Senpai (セフレのセンパイ)
5. Sefure no Senpai Gaiden: Nana-senpai no Jijou (セフレのセンパイ外伝　ナナ先輩の事情)

Note: The manga was officially compiled into a single volume by Got Comics, including its side story and an extra chapter.