If you're referring to cut scenes that happen during foreplay mode (i.e. not counting the CGs that show up during weekdays), there are four that can be triggered. There is the kiss scene, Tocchan giving Haato an oral (as he calls it), the shibari scene and the teacher-student roleplay scene.
This is according to my playthrough so this might be inaccurate. For the shibari scene, I think Tocchan has to be a sub bottom. You must have the rope sex toy to make if work, obv. When that scene triggered for me, it was the second time I had Haato use it on Tocchan. It might be important to note that they've had sex more than 7 times at this point. For the teacher-student roleplay, you need to have the gakuran costume to be able to trigger it. The scene triggered the second time I had Tocchan wear it.