SVDVD-251 - Sound of juices and machines echoing in the office, a frustrated OL riding a vibe

It's a trivial concept, but the actresses losing control to the machine vibrator are quite good, making it an interesting watch. There are 5 people featured; the second is Nene Masaki, and the fifth is the glasses-wearing teacher on the cover, Shizuka Kanno. The reactions were best from the 2nd, 4th, and 5th, and I personally liked the 4th one best. My complaint is that the machine vibrator keeps slipping out. It's a shame that whenever they're about to climax, their hips lift and it falls out. Also, the 1st and 3rd didn't seem to feel much. It seems the intensity of the machine doesn't work for everyone.

*Personally, the second one was the key point. What kind of actress is she?