Nebel is still the undisputed kamige of the genre and nothing comes to close to Kana as NTRSQueen.

The game has a work phase where it depends on the player's performance how aroused and what opportunities the bull gets to molest Kana. Monitoring only her heartbeat is a subtle and genius way of creating tension. Later on it's even possible to use spy cameras of different quality.

Then there is an afternoon phase in a large town with tons of activities, where Kana has her own varying schedule. Moving around the town takes time and the player has stuff to do too, so the only way to monitor Kana is by calling her on the phone. The phone is not always reliable and you have to know her schedule to properly interpret the clues.
The bull has blackmail on Kana and there is a chance he will be trying to seduce her depending his arousal and schedule. If you fail to show up in time to prevent the event she will get molested.

During the act there is both visual and audio indication that someone is having sex at the place. The player can even peep at times, but never clearly enough to tell the identity of the girl, never completely breaking the suspension of disbelief that it could be someone else. After the act there could be stains and condoms left over at the place indicating what happened. When you find Kana afterwards and ask about it, she will be flustered and tries to evade the question. Sometimes she will be unavailable for the rest of the night and you might not even be able to meet up with her before work and see her flustered expression over disappearing for the night. Running around frantically only to find out she has been being fucked for hours with no way of reaching her until tomorrow is incredibly hot.