PACHINKO SEXY REACTION / Sammy / Arcade
You would never see this game make it outside of Japan, but if it somehow was localized the most apt title for it would be "Quarters For Tits."
You start out by picking one of three young anime ladies with Ginormous Gazongas, then proceed to play a pachinko-slot hybrid. Each round begins with the lady displaying some sort of provocative costume or outfit she will slip into if your Pachi skills are elite enough. I still don't totally understand the rules from there, but you control a dial to fire out the pachinko balls onto the playfield, and sometimes when you land in the ball slots a slot machine will spin ... get enough of these and eventually you enter Fever Mode, where you have to scatter the balls into all the receptacles at the bottom to destroy the background within a narrow time window. Apparently the better you do at Fever Mode, the more nakkid the anime lady gets in the cutscene that closes out that particular outfit.
Anyway, each girl goes through four or five outfits in this way, then you move onto one of the other girls. If you Pachi your way through the whole starting three, two more challengers appear -- Bad Student and Nice Teacher. There's actually a little ending and credits sequence if you sit through the whole thing.
Now, a little real talk here, if we can. Most of your healthy, heterosexual men enjoy a set of large, shapely breasts. There's a certain line where it crosses over into specialized fetish territory, however, and I think the physics-defying melons on display here are disproportionate enough to qualify. So for most people this will simply be about watching the weird spectacle of it all than that they will actually have the advertised "sexy reaction." Crazy mammaries aside, some effort was actually put into giving each of the girls distinct personalities, along with their own voice acting. The one with the short blue hair, for example, is less enthused about being subject to your perverted whims than the others and will celebrate when you lose a slot spin and talk shit when you're about to run out of balls.
This barely qualifies as a "game" since you can just brute-force it with enough money and patience, there's no real way to lose except for quitting, and the dial aim seems to only have a very vague influence on where each ball ends up. I bet it still drew at least a decent audience due to the combination of flashy light addiction triggers and salaciousness, a combination I'm actually surprised we don't see more often on casino floors.