Oh my goodness, this was posted back in 2015 but no one uploaded it here (I'm guessing because people back then were still confused as to what these cover images were, since they interrupted the flow of the regular 4koma but sometimes looked related). I only found out about it because it was listed in an index of all the side stories that's in the back of one of the artbooks that they also sell. Anyway, predictably, this isn't on DLsite.

I've got a Yahoo Japan Auctions saved search for this and the other two comics that aren't on DLsite (which happen to both be from the same time as this one); I'm hoping that I can get a print copy of them from someone selling their used copies at some point. Unless Hachimaki rereleases them first, that is...

Cute Kagerou!
It's interesting how this artist's style is recognizable, he's not neither the first nor the last to draw simply and cute, but this style stands out!