It's a NTR, and I must say, as far as any that I've watched, this one is just sad. It originally revolves around a mother's incestuous feelings towards her son, but then progresses into the son realizing his own feelings towards his mom, but her being taken away by his "good friend."
The mom's actions are just downright awful, by the second episode, she's turned into her son's friend's( whose name is Shin btw) bitch. She was originally bribed into the sex, but soon enough does it on by her own will. But obviously, if you're watching this, you're probably more in it for the sex anyways. The sex is pretty much all vanilla up until the second episode where she uses a double-ended dildo on her son (so if you're not into that you might not want to watch, but seriously the son is so girly you might not even care) while he's tied up and dressed as a maid.
Another possible turn-off might be how they constantly show the son masturbating to his mother (but that actually plays a big role to the story).
There's also a few good mother-son incest scenes to look forward to if you're into that, but if not, don't knock it, she gets fucked by Shin for a good majority of the hentai anyways.
By the way, she was bribed, and she does mention how it was rape, but it's not extreme, to be honest, I feel like she raped her son, whereas in her case she actually wanted to do more with Shin. Just mentioning this in case you dislike rape, it's not really a rape centered hentai.
Overall, I recommend it, good fap material, interesting story line (not that there's a lot of a story, but it's interesting nonetheless), and good art plus sound.
