https://vndb.org/v23388
http://www.getchu.com/soft.phtml?id=1015109

One of the main gimmicks is how the MC is gifted a stopwatch that can manipulate time a la Chronoclock, but it only pauses time for 5 minutes before his sexual misadventures (harassment activities) are punished with a fist to the face as seen in 7-14 and 40-46. As far as I understand, he mainly uses it to gain the hearts and minds of his female love interests. Also, the black-haired girl is his sister, who is revealed to be a massive bro-con as she wanks off to him in the first few chronological CGs.

Base +6, cycber +14, shshshsu +4, Curie +11, Shurikensei +8