Alot, best guess atm.
You have the standard CGs and progression for H events.
The minigames and side-jobs.
The combat H, of which there looks to be a metric f-ton of H skills (which CANNOT be used in the demo btw, even with cheats, the assets are not there) but these include all 3 holes, and even extra such as buttjob, thighs, armpit, hairjob, cunnilingus and basically every sex act.
I imagine in regards to unique CGs, I think 100 is a fair estimate. But when you include the light/dark skin, all variants and the gameplay on top, it certainly seems to be a VERY huge undertaking.