Sweet Room is a mobile drama, with 5 minutes per episode that's split into four stories. All of them are playing in the suite of a hotel and somehow center around love and lust.
I think, this was only made to show some nice kissing and erotics, without getting too explicit. While watching Hirokis scene, I really wondered how they managed to get him and if the other scenes were like that, how they managed to get the others, too.
Hiroki's part was very beautiful, though it was a bit awkward and the story only unfolded at the end, so most of the time of that 15 minutes, you were sitting there like "Okay, what, why and how?"
The other stories weren't as erotical as Hirokis, but also included bed-scenes. Actually, my favorite story was Mukai Osamus, since it's the story of how he has a lovely birthday night with his girlfriend since four years.
The others were rather showing a different side of love, instead of bed scenes.
All in all, this is a mobile drama and for that I liked it, but at some point I always wanted to turn it off, because it got boring to watch them kiss. So 2* instead of 1, for the actors they got there.