Episode 4 is out by KuroNeko, but for some reason the direct point-black link to the torrent isn't working. It's still possible to get the well seeded torrent for example by getting the torrent from mininova:

Episode 4 - KuroNeko (Mininova download page)

No doubt the direct link / server will be fixed at some point, and the proper link can be posted here. But until then this seems to be the easiest way.

Edit: A fine episode once again. But Rika's hourglass is quickly running out of sand.