huh? Is this Kogasa's sister or a random yuokai?

That's Kobato!

Wait, did the artist tag her in pixiv? Because if not, I will say the cliché "Don't tag it if it's not certain what or who it is."

Schrobby said:

That's Kobato!

Glad I'm not the only one thinks she's Hasegawa Kobato. But hey, can't be sure about it. The girl dresses normally in black remember?

Great, now I'm reminded of a certain Warugaki doujin.