Yumi is tied up on a bed, legs spread, and the whole game is just you and her and a box of stuff. The first thing I did was grab the egg toy and push it in, one after another, watching her squirm. The physics are janky as hell, like the dildo clips through her thigh sometimes, but honestly who cares when she's moaning and her pussy is stretching around that black silicone. You can slap her tits, twist the nipple vibrators up to max, and she reacts with these little gasps that made me want to keep going just to hear the next one.
The schoolgirl uniform is half torn off, which is a nice touch, and her face goes from bored to desperate depending on how rough you get. I spent way too long trying to line up the vibrator on her clit because the hitbox is weird, like trying to plug in a USB cable in the dark. But when it finally connected, the way her hips bucked was worth it. The reward system is simple, fill her excitement meter and she cums, then you get a little scene. Nothing crazy, but it works.
One thing that bugged me, the sound effects are super repetitive, same wet squelch every time you insert something. I ended up muting it and playing my own playlist, which actually made it better. If you're into bdsm slave stuff without any story getting in the way, this is a solid time waster. Just don't expect deep writing or anything, it's pure mechanical teasing. Use the egg trick early to build her meter fast, then switch to the dildo for the hard finish.