This is yet another of those Japanese ero-games, albeit one of the weirder ones, both in terms of the fetish it involves and the way that it poses a moral question to the player.
The protagonist is this guy named Tetsuya, and for some reason he’s obsessed with inflatable love dolls, and to a lesser extent inflatable things in general. (Seriously; in the game there’s a scene where he blushes about a pool toy). After some exposition, the story kicks off with him at the park, where he sees what looks like an inflatable girl walking around in Daisy Dukes and a camisole that shows off her midriff—and the air plug that’s right where her belly button would be. Tetsuya can’t help but stare at her glossy skin as she walks around. Much to his surprise she walks right up to him and says “You can pull my plug if you like, but you have to do it during the next ten seconds.”
She gets to two before he works up the nerve to do it. She deflates on the spot, and apparently whatever magical spell was keeping everyone but Tetsuya from noticing that she’s an inflatable love doll breaks. He hurries home with her, and after agonizing over the matter for a bit, he pulls her clothes off and re-inflates her. This is where you get the first sex scene, and learn that if you inflate a balloon girl with your mouth, she’ll become… suggestible. Afterwards, she goes on her way, and that’s that. This whole part is scripted, and takes something like 20 minutes to get through.
From there things get much more open-ended, and the game becomes much more interesting. Tetsuya starts noticing other “balloon girls” around town—a generic “heroine,” a sexy teacher, a nerdy girl, a tomboy, etc.—and it’s up to you to decide which ones he should pursue and how. Not content merely to tantalize, this game puts a moral choice in your hands: Will you treat these balloon girls as people or as objects? When you find a girl you can try to sweet-talk her, or try to forcibly deflate her and take her home. The effect this decision has actually varies depending on the girl; some will ignore your advances no matter what, and some don’t really mind being “caught.” Regardless, one way or the other you’ll get more sex scenes this way.
After each sex scene, you have another moral choice to make. You can let the balloon girl go on her way, or deflate her again and stick her in a drawer for later. Later in the game Tetsuya also finds a “balloon store” where he can actually sell off captured balloon girls for money, and in turn buy certain things, including a magic spell that lets him deflate balloon girls from a distance.
Over the course of the game there are various events, and if you score enough points with a particular balloon girl you can get her special ending. Most of these involve Tetsuya having some kind of long-term relationship with her, though some of these require you to be nice, and some require you to be mean.
There are also three special endings. It turns out the balloon girls know each other, and the game keeps track of your overall reputation with them. If you’re nice to enough of them, they start to trust you. If you max out your positive reputation, you get a special ending. If too many of them disappear, they’ll start to get suspicious. This makes it much harder to talk them into doing anything with you, and if you push things too far there are consequences—the special bad ending.
If you max out your positive reputation, the girl from the park visits Tetsuya again asks if he wants to visit Balloon Land, the place where they come from. If you accept, he winds up visiting this surreal other world where everything is inflatable. If you’re willing to investigate a little bit you can unearth all kinds of backstory too. Balloon Land was supposedly founded by a man and woman who were turned into balloon people by an evil wizard, and to their surprise found that they could reproduce. The people there are about 2/3 female, but there are males, and there are also balloon girls with different patterns of seams (or no seams at all) and in different colors. Children are pulled from their mothers deflated, and grow to maturity over the course of about 7 years, after which their genitals and such finally form. The fact that chances of pregnancy among balloon people are relatively low, combined with the relative scarcity of guys, and the fact that there isn’t a whole lot else to do there, all mean that balloon people spend most of their time screwing like rabbits. While you’re there the balloon girls are all really excited about the opportunity to meet a “squishy boy,” so you can get a couple more sex scenes there, including one with a translucent red balloon girl. Plus if you bought puncture repair kits (which for them are like some kind of miracle cure that can bring back the dead) you can get some more special sex scenes besides.
If you push your negative reputation as far as it’ll go, you wind up finding out the hard way that under certain circumstances balloon girls have the power to turn normal people into balloon people. One of them takes the opportunity to put her mouth around Tetsuya’s belly button, and when she pulls away there’s a plug, which she pulls. He winds up being captured by a girl with a similar inflatable fetish, and eventually turning her into a balloon girl before heading out to figure out what to do next.
Finally, there’s this normal girl named Haruka who’s always bugging Tetsuya even though he shows no real interest in her. If you manage to accrue enough money (you have to capture and sell 3 balloon girls, which puts you dangerously close to the second special ending) you can buy a “balloon potion,” and use it to turn her into a balloon girl. That nets you the special ending where she completely falls for Tetsuya.
All in all, this game is at once surreal and thought-provoking. Not everyone is going to share the creators’ weird fetish, and not everyone is going to appreciate using their brains that much for interactive pornography. Fortunately during the actual sex scenes the only thing you really have to do is click the “Next” button, but switching between the two extremes is kind of weird to say the least.