https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_494114/
https://www.dlsite.com/girls/work/=/product_id/RJ01309518.html

Part 4 - [Synopsis]

When female investigator Manaka Shizuku discovers that what she thought was an aphrodisiac is actually just a vitamin supplement, she is shocked.
This means that she has been reacting to Arikawa's caresses and becoming lascivious of her own will.
However, unable to accept this, Manaka seduces Arikawa's colleague, Natsubori, to prove that she was not in love with Arikawa but was only feeling it because she is a bitch who falls for anyone... Furthermore, Shimotsuki, a former investigator, appears and takes over as Arikawa's partner, revealing her lascivious nature...!?

Base +22

Where's the previous volumes of this?

Base +6