Super Jack is a strip-Blackjack game for the PC-88, released in 1988. You play against a cute anime girl, and the more you win, the more clothes she takes off. I'm very bad at Blackjack, so I have yet to beat this game. (It's very fun!!)
The game was made by G_Club Software, and aside the Sharp-X68000 port of the game, I believe this was their only release. It's probably the most solid PC-88 game I've played, and it's one of the few with an English patch (though, it's entirely playable without one).
The game doesn't quite follow the casino rules of Blackjack from my recollection, though I admittedly don't know too much about how to play. The two keys you use throughout the game are space (add a card) and enter (done drawing). The game also has a very nice soundtrack, though it gets grating when you hear it over and over again. If playing in V1 mode, the soundtrack doesn't play.
The goal of Blackjack is to get as close to 21 as you can without going over. There seem to be other rules that I don't quite understand, such as getting the same number as your opponent in more cards means you win against them that round. Regardless, it's pretty easy to get the hang of, and you're mostly going to struggle with the RNG.
There are multiple stages in the game, with each having a set number of rounds to beat. When you lose a round, the counter goes down, but if you get exactly 21, the counter goes up two instead of one. I'm not sure if the game has some sort of mercy system, but it seems like if you get knocked down a level or two, the game is a bit nicer...
I'm not sure how many stages there are in the game. I recall in the Sharp-X68000 version that she appears to be hesitant about taking off her underwear, so you end up playing an extra stage. There are also sometimes special sprites for when you lose a level while she has less clothing on. For instance, if she has her shirt off, she'll hold her shirt to her chest with a cheeky look on her face if you end up going down a level. I'll report what happens at the end of the game if I ever manage to beat it.
Are there any resources for Super Jack? No idea. I plan to post a playthrough once I finally beat it, so I'll make sure to link that here when it's complete.
This was one of the first PC-88 games I ever played.
I also feel like I should mention this somewhere, but I don't actually get off to any of these games. I find them genuinely fun to play, and the more mature aspects of the games just feel silly to me.
