They look like characters from hentai_ouji_to_warawanai_neko, tsutsukakushi tsukiko and azuki azusa

I almost made the mistake of changing the tags before searching. It could be, could not be. And the reason is ...

"A 2010-current light novel series by Saraga Sou, with illustration by Kantoku"

This image has no Source to help my curiosity.

Made even more confusing by the fact that the girl on the right has the same eye color as Tsukiko (different from Shizuku), but no hair clip.