I remember their being bio pages on the girls in the classroom (measurements included). In fact, a sketch Ken did is my go to when I need to explain cup size to others.
A lot of people forget (or don't know) that Ken Akumatsu started out as an erotic doujinshi author.
Just like any other thing, there are enjoyable current isekai titles (to one's liking) if you search well enough.
If you're looking for good modern isekai, I have some much better titles for you. They are listed in this video here (yes, an actually GOOD anime recommendation video):
For convenience's sake, I'll list them here as well for those who don't want to watch the vid:
Mezametara Saikyou Soubi to Uchuusen-mochi Datta no de, Ikkodate Mezashite Youhei Toshite Jiyuu ni Ikitai: Yes, that's the actual name. Full name in English is "When I Woke Up, I Got the Strongest Equipment and a Starship, so I Went and Became a Mercenary in Order to Live as I Please while Aiming for a Detached House". The manga is an adaptation of a light novel series whose author was a huge Elite: Dangerous fan, and the series is basically an (un)official adaptation of Elite: Dangerous with the serial numbers filed off. The main character was a normal 27 year old salary guy who liked playing his world's Elite: Dangerous ripoff, only to fall sleep at his computer one night and suddenly find himself transported to a world identical to the game, inside a powerful starship identical to the one he piloted in game, which was one of the best ships in said game. Thus, its a sci-fi isekai with a protagonist who is rather ordinary himself, but has an awesome ship to compensate for it. Its a harem series as well, where the protagonist actually fucks his harem (though the manga tones down the blatant sexiness of the light novel), and the harem aspect is an in-built part of the setting, with the haremites being members of the main character's crew.
Shinju no Nectar: Also known as Nectar of Dharani, its a fantasy isekai, but its not set in a medieval fantasy world, but one currently going through an industrial revolution, so things like guns and sarin gas are present. The main character is summoned by a princess on the run from enemies of her country, just as she's being cornered by them. The princess meant to summon a great hero, but she summons the main character instead, and he's just some normal, low wage slub from Japan. Thinking all is lost, the princess is suddenly taken over by a split personality who powers the main protagonist up...by feeding him her breast milk. Yeah. For those who don't know, this story is from the creators of Seikon No Qwaser (Qwaser of the Stigmata). Apparently, our main character, Kai, only gets this power up because he's human (humans are rare in the world this story is set) and the princess suffers from some kind of curse, and Kai is one of the lucky few who benefit from this curse by consuming the main heroine's breast milk while in her cursed "Ambrosia" state. The interesting part of the manga is the complex politics at play, as its a fantasy world turning towards science and technology, and away from magic, leading to political upheaval among the nations of the setting. Magic itself has been disappearing, leaving Ambrosia as one of the few sources of magic left. Also a harem series and has beautiful art.
Nigoru Hitomi de Nani wo Negau - Highserk Senki; Also known in English as "What Do You Wish For With Those Murky Eyes: Record of Highserk War". Notable in that it takes the basic isekai plot and rams it through a woodchipper. The main character was a normal Japanese salary man who died on Earth and reincarnated in a medieval fantasy world. But not as some overpowered hero destined to save the world. Oh no. He came back as a normal, run of the mill foot soldier fighting on the frontlines of a brutal war. The main character has no cheat abilities whatsoever, and while magic exists in this world, its far weaker than in a high fantasy setting. The best word to describe this manga is gritty. There is no light fighting the darkness here; its a dirty, dangerous world. The main character doesn't gain levels and become OP. He gets better the old fashioned way; by surviving on the battlefield a little bit longer and gaining the necessary skills to continue, which only allow him to survive on the battlefield just a little bit longer the next go around. Basically, everything an isekai is supposed to be (bland power fantasy wish fulfillment) is balled up and thrown out the window.
And since I brought up that video, I will heartily recommend the two other manga it mentions:
Rebuild World: A science fiction manga (adapted from a light novel) taking place in a post-apocalyptic cyberpunk setting, starring a young man trying to make it as a relic hunter in order to survive on the streets. While traveling though some ruins, he meets a "friendly" AI who offers to help him find success, and in exchange, he will ultimately do something for her. A very interesting, dark story with beautiful artwork.
Ningen Fushin no Boukenshatachi ga Sekai o Sukuu Youdesu: Known in English as "Apparently, Disillusioned Adventurers Will Save the World", this is a traditional fantasy story (adapted from a light novel) with a unique twist. The main characters are a bunch of rejects who were all thrown out of their previous parties or organizations for various unfair reasons and betrayals that leave the cast with a massive amount of emotional baggage. They decide to form a party together because they literally can't trust anyone else due their pasts causing them to lose faith in people, but since they all understand what it means to be betrayed, they decide to party together so they can earn some honest coin together.