http://mintmanga.com/saezuru_tori_wa_habatakanai/vol4/22?mature=1#page=37

It's the fanart by my tumblr friend - nevergiveupondreamsfan. They cropped it so that the credits are invisible. She will be disappointed and sad, to say the least. You can see more of her awesome works on tumblr http://nevergiveupondreamsfan.tumblr.com/MY%20SAEZURU%20FANART , that's where she also clearly asks to not remove the source.

After seeing her works you may thank her by using tumblr Ask (you can do it as anonymous) http://nevergiveupondreamsfan.tumblr.com/ask
.