Koikatsu is a game that sounds mind-blowing on paper: It’s a hentai dating sim in which all the character are created by you. Using the game’s remarkable editor, you get to build your dream waifus or recreate your favorite anime characters, and then romance them to your heart’s content. There is no denying that the game has amazing customization options, though this tragically comes at the cost of actual gameplay depth.

Your custom avatar is a relative of a school principal who runs an academy exclusively attended by girls. She is concerned that her students will be unprepared to deal with boys once they graduate, so you are forced to transfer to her school and become its only male student. You are then also tasked with starting up a club where girls learn about interacting with boys, which is really just your personal harem.
Before starting the game’s story mode, there is potentially a lot of creation to do. The game’s default class roster has room for over 30 characters, which can be expanded significantly if you’re feeling very creative. You don’t need to fill every seat and can transfer in new characters whenever you want, but even so you’ll likely want to prepare quite a few characters before starting.

The character editor is absurdly detailed. You can reshape any character’s face and body down to the most minute details, including the naughty bits; you can even opt to censor those if you want the authentic hentai experience. The editor is also very accessible. I’ve been able to create many good-looking characters by using its randomization feature until something came out that inspired me, after which I could edit the details into the look I wanted.
Besides the physical appearance, you also get to tweak a character’s personality. There are dozens of anime stereotypes to pick from, each with unique voice-lines. You then set their likes & dislikes and can tweak their behavior further with a variety of traits. For a fun combination, take the yandere personality and give them the “suddenly appears” trait. Not only will you be able to “enjoy” some uncomfortable, borderline-obsessive dialogue, but you’ll also find yourself running into that character in the weirdest places. Congratulations, you got yourself a stalker!
The characters you make are stored in .png files, which makes them easy to share. There are dedicated image boards for developer Illusion and I’ve seen image cards being shared on Pixiv and other social media. You can just save the image, put it in the right directory, and it works instantly. This is especially useful if you’re looking for licensed characters that would be difficult to make yourself.

I spent the first five days of owning this game doing nothing but creating characters. Eventually, though, I started playing the actual game. And it’s not very good.
Calling Koikatsu a dating sim is honestly disrespectful to the genre. Naturally, the characters are very simplistic and don’t offer any kind of meaningful story to explore as you grow closer to them. Each girl just goes through simple daily routines, most of which involve sitting around, doing nothing. There are no interpersonal relations between characters, no interesting events, and you’ll find yourself looping through the same handful of dialogues constantly.
The only “dating sim” aspect of the game is that you have to fill up a relationship meter with each girl, which increases by talking with them about 3 different topics. Alternatively, you can let them quiz you about their likes & dislikes (which you set yourself) for a larger boost to the meter. There is also an additional H-meter representing how horny the girls are. Depending on their personality type, some girls will be willing to romance you even with a low overall relationship, so long as the H-meter is high enough.

Maxing out both meters is absurdly easy though. I managed to do so on most of the characters within an in-game week on my original run, and have since managed to optimize it down to 2 days. The game has a timer mechanic that limits how much you can do and has stats you have to train up, but these objectively don’t work. The timer especially is hilarious because it doesn’t advance when you do activities with the girls. You can have 38 consecutive lunches and get the relationship bonus from all of them, and you’ll still have plenty of time to kill afterwards.
In fact, losing relationship points is so impossible you’d need to actively sabotage yourself to do it. You can sexually harass girls, be caught peeping on them, invade women-only spaces, even cheat on your girlfriends in full view, all without any consequence. The only way to actually upset girls to the point of them refusing to talk with you is by breaking up with them, and even that carries no penalty to the relationship meter once you’ve apologized.

The game also lacks basic features you’d associate with a dating sim. You can’t kiss girls, you can’t give them presents, can’t hold hands, can’t hug; the only physical contact you can have is giving headpats or “accidentally” touching their breasts. The actual dates you can go on are always the same generic visit to town unless you have the DLC. Even if you do, there are only 4 locations to pick from with very little interactivity each, and you still have to do the generic date first with each girl before you unlock them. What???
You might also be wondering what that club I mentioned earlier is about. As you recruit women into the Koikatsu Club, they deviate from their usual schedules to spend as much time as possible in your clubroom. You can do “Koikatsu” with them, which are short, romantic dialogues that boost the H-meter. Besides that and unlocking some minor features, it’s really quite pointless and actually makes the game less fun. The school is lively when you start out and all the girls have their club activities and schedules, but towards the end game much of the school is abandoned because everybody is sitting around in the same room, doing nothing. You can’t even avoid or mitigate this, because girls will randomly join the club of their own volition without your approval.
Koikatsu wants to be more than just a tool for customized hentai, but it also doesn’t want to actually put a meaningful game between you and the hentai. This sadly means we get the worst of both.

The hentai scenes are impressive at first. They seemingly offer an endless list of different positions to try out and you can use your hands, tongue, and toys to further interact with your partner. There are even secret romance spots to discover with unique positions. However, it all looks very janky and gets old quickly.
The 3D models do their best to behave, but things are inevitably going to clip together in awkward and unappealing ways. It’s also obvious that curners were cut in the animation department. The actual thrusting generally looks fine as far as an animation loop goes, but they didn’t want to animate your player character touching the girls or actually using the toys. Instead, the moment you try to do anything but watch the animations loop, your character will turn invisible. You’ll be left with disembodied hands, a tongue, and genitals, which looks absolutely awful.

Some scenes don’t even work properly if your characters are build in certain ways. I made my main character quite tall because I myself am a real-life titan. This often left normal-sized characters doing very funky things to the air underneath my avatar. Well-endowed characters may also pierce right through their partners and you’ll frequently end up with characters clipping into the environments and furniture, as by default all sex scenes will just immediately commence on the floor at the exact spot where you approached the character.
Those secret romance spots I mentioned are an exception to that, but they are often very disappointing. There are decent ones here and there, but most have strange criteria required to unlock them, are very restricted, or both. For example, the love sofa in the club room only allows you to use 1 position, for no real reason other than to be obtuse. Even more bizarre is your bedroom. Inviting a girl to spend the night will still result in a normal love scene on your floor. When you then proceed to the next day, there is a random chance of triggering ANOTHER love scene where you actually use the bed like sensible people. Why not just let people choose?

I give the game a hard time, but it is genuinely fun to create good-looking characters and the H-scenes, while flawed, are appealing if you get them working correctly and tinker around with community mods to lift some of the stranger restrictions. However, what kept me coming back to the game was actually its story, as bizarre as that sounds.
The actual characters you make yourself may have generic dialogue, but the game also features a number of preset story characters that trigger visual novel segments when you find them. These take you through short, but fun storylines in which you befriend and eventually fall in love with these girls, which almost play like a more traditional dating sim. There are no choices to be made, but the writing is endearing and often lightly mocks familiar tropes. These also lead to unique sex scenes, which greatly benefit from their restricted design.

These storylines, in combination with the game’s other strenghts, make Koikatsu serviceable for what it is. I hope Illusion or somebody else gets to iterate on Koikatsu‘s ideas, because this level of customization in combination with deeper gameplay and more polished scenes could become a landmark title for hentai games. As it stands, it’s something I played through once for the story, and then fired up from time to time to design a cool character.