From BookLive:
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. This book includes the newly-drawn exclusive "Sex Friend Senpai Ch. 2.5", which depicts a secret sex scene on campus!

1. Sefure no Senpai 1 (セフレのセンパイ 第1話)
2. Sefure no Senpai 2 (セフレのセンパイ 第2話)
   2.5. Sefure no Senpai 2.5 (セフレのセンパイ 第2.5話)
3. Sefure no Senpai 3 (セフレのセンパイ 第3話)
4. Sex Friend Senpai Side Story: Nana-senpai's Circumstances / 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～)

C103: Nana-senpai to LoveHo de Cosplay Ecchi SeFri no Senpai Bangaihen (ナナ先輩とラブホでコスプレえっち 〜セフレのセンパイ番外編〜)