The official justification for this series is that Japan's demographic crisis has forced the government to pass a law in favour of promiscuity and sex lessons in schools. No, not just sex education. The lessons are practical.

This probably sounds horrific... but it's far better than you'd think. It reminds me (a little) of the sex education sketch in Monty Python's Meaning of Life, actually. The teacher reminds the boys to pay attention and announces that anyone who doesn't ejaculate will have to stay behind after class. ("Ehhhhh?" complain the boys.) Also, anyone doing anything the girls don't like will get summoned to the staff room or get put down by the girls themselves.

"No, nothing for you. Weren't you complaining about me being on duty, Kimura? You'll get a hand job and that's it!"

Consensual. Occasionally approaching "witty". Respect for the girls (admittedly within a mega-hentai context) and educating the boys about correct behaviour. It would almost be possible to approve of this series.

The story's pretty rudimentary, as is the characterisation. (The brother, Shindou, is a Mute Male Protagonist. The perky gyaru sister, Rino, does all the talking. Even when their mother knocks on the bathroom door, she never speaks either.)

Anyway, Rino fancies Shindou. They consummate their affection in various situations.

This one's something of a long-runner, with six episodes from 2019 to 2023. The first episode started with a non-consensual gang bang, as the girls in the school lacrosse club tied their coach/adviser (Kuroda-sensei) to a chair and had their wicked way with him. Fortunately, the show improved later. It's become a normal anime school comedy, with a fun, likeable cast. They goof off at the beach, play pranks and unfairly blame Kuroda for stuff.

Surprisingly, the explicit sex content makes the series better than many mainstream harem TV anime. It's more honest. The harem genre in general defaults to prick teasing and bullshit, with a side order of "refusing to choose because that would break the formula". Girls get locked into a holding pattern of obsession around some unimpressive bloke they'll never get... but not here. They all catch him! You can see exactly what they're getting from the relationship. (Great white spurts of it, in every episode.) Everyone seems happy with the "share and share alike" arrangement, so fair enough.

Ep.6 is even funny, with four girls deciding that it's time to recruit a fifth into their Kuroda's Dick Club. (They regard his penis as communal property.) Their initial recruitment attempts are rubbish. Anyway, this show's surprisingly okay.

Our hero, Uno-kun, is meek and good-natured. He's outside with his telescope one night, watching the stars, when an enormously tall and buxom topless girl comes out and jumps up and down. Imagine exhibitionist callisthenics.

"Good evening. Umm, telescopes are vulnerable to vibration, so I don't suppose you could move a bit further away?"

This easy-going exhibitionist is Momota Kaedeko and she's the star of this hentai. She made me laugh. When caught having sex in the school library by the class president (Ikkaku Rose), she complains about missing out on an orgasm. (Rose: "And you think I care?") When the class president says she'll never understand people who perform obscene acts in public, Kaedeko not only recommends it enthusiastically but invites Rose to join in for a threesome. "It feels out of this world! Join us and you'll understand, Rose-chan!"

Similarly, when Uno-kun doesn't recognise Kaedeko at school, she gets her tits out and says "don't you even remember these?"

It's charming. There's more to the plot and even the characterisation than just sex. Kaedeko's not merely a sex maniac, but instead a girl who's had to change schools repeatedly because of her father's work transfers, so she's chosen to live in the moment and spread happiness. Similarly, Rose is more than just a puritanical dragon. She's trying to push Uno and Kaedeko into actual romance for the sake of improving their long-term relationship. (Which, in fairness, will probably happen.) Rose wants to hear proper love confessions from them. I liked her.

This one's nice and quite funny, in its gentle, understated way. I laughed.