The "plot" is pretty simple: girls are cursed and that´s why they need semen. If you are a veteran in hentais, you have probably came across something like this before.
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Positive aspects:
(+) Even though the art and animation are not top notch, they are above ok-ish or fine. They are good. Solid good. Although I have to pinpoint that (look for the negative aspects below**);
(+) Dark-skinned, MILF, pony-tail, blonde, model student and etc. The diversification at this regard is nice and very welcome;
(+) Even though his face is not shown, the guy is not the usual ugly-bastard type with a creepy and annoying voice that we usually see in hentais like this one.
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Negative aspects:
(-) **Their bodies looks all the same or are very similar, which is kinda boring; it also lacks in details - it´s plain; (Except that one of them is dark-skinned, for a bit of change).
(-) No transition between the scenes; or from a sex position to another, it´s random and kinda of rushed.
(-) Most of the sex scenes are the same; repetitive. Specially in episode 01. In episode 02, however, it´s when they add a bit of kinkness (anal and it had the best oral scene of the hentai - easy 8/10 for that part). But again, in general, the sex scenes are repetitive and the same.
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CONCLUSION: In general. A fine hentai that could have been way better if it werent for those negative aspects, obviously. Still, it´s a solid and/or safe recommendation either to veterans or to those joining this high quality culture xD