It's essentially a shortform hentai. Not even borderline, this is way beyond the border of "Ecchi", at least as it is considered as in the West. Animation's pretty, though, gotta give it credit for that, at least.
It's almost soft hentai, but everything is covered by bears so you don't see anything anyway. The plot is nearly non-existant. It's just an excuse to fantasize about student/teacher relationships.
*as you can tell, SPOILERS*
When i first saw it (about 5 minutes), I didn't even know, what was it about. Then I realized what it actually was. Its basically heavily censored hentai, which is in my opinion pointless. I saw original piece, can't say I didn't enjoy it, but the problem is, why would you censor hentai to be considered as "anime" in the first place?
It had interesting plot, but a thing I didn't understand was overall motive of Kugi.
I haven't seen this version, but the first 5 minutes were kind of confusing because of heavy censorship. If you want to watch hentai, but you want a story, I guess you can watch this. In my opinion is kind of pointless to make hentai into anime, because the whole anime won't have as many information as original hentai.
If you ask, I haven't really even watched the original too much, because It felt a bit long and I mostly skipped boring parts. Overall, if you want to see it, I really don't care and I don't have any intensions of stopping you. Just remember it is just censored hentai with not that strong plot.
Please don't focus on this review too much. It's just my opinion about the whole concept and I don't write reviews too much. If there are any mistakes, I apologize.