To be clear, it's a hand mirror, and the "club"/party in the basement near the end of the game. Can't miss it, it's impossible to progress without doing it. If you're having trouble though, it starts with one of the kitsune to the left near the bar.
Thank you for responding. I finally managed to do it. The problem was I only played the "other" way and didn't do the route that actually had the event. Amazing work and attention to detail (especially that bit between Mahir and his friend).
