Identify Old 3d Japanese game about a sister

[ᴏᴄᴛᴏ]

I forgot it's name but there's a game on this site where you live with your sister, you wait for her to come home from work, you can follow her and spy on her, but that's pretty much all I can remember. The graphics are VERY basic, very few polygons and I don't think it has any textures. There are a couple of games on this site from that dev, but that's the only one I can remember.