Feminization: I!~ being a girl feels nice!~

Premise: due to an accident from tuesday through thursday every week he switches bodies with a certain girl, and turns back on friday.

In ch 1 she texts him that it's her father's birthday today, so you must do whatever he asks. (Of course, he wants her virginity as a present.)

(成年コミック) [座間翔二] にょたいか・俺！～女の子ってキモチいい！！～ 1
https://www.amazon.co.jp/%E3%81%AB%E3%82%87%E3%81%9F%E3%81%84%E3%81%8B%E3%83%BB%E4%BF%BA%EF%BC%81%EF%BD%9E%E5%A5%B3%E3%81%AE%E5%AD%90%E3%81%A3%E3%81%A6%E3%82%AD%E3%83%A2%E3%83%81%E3%81%84%E3%81%84%EF%BC%81%EF%BC%81%EF%BD%9E-1-%E3%82%82%E3%81%88%E3%82%B9%E3%82%BFBEAST-%E5%BA%A7%E9%96%93%E7%BF%94%E4%BA%8C-ebook/dp/B00HFTQVJI/ref=sr_1_15?s=digital-text&ie=UTF8&qid=1474094562&sr=1-15

looks like this is from もえスタBEAST

Base +6