Olympia Soiree, unfortunately. I saw that it had a positive reception and the art was all sparkly and pretty. I should've known better though. The premise of it was kind of dubious to me, to begin with, but I thought the execution and pacing (for the romance) was also lacking. While it's not the worst game I've played, it's definitely the most disappointing.
At least I know now to think twice about, or at least do my research before playing another game written by Katagiri Yuma, like Tengoku Struggle, which already got some mentions here. Her works seem to have a common theme I've noticed, that I don't care for...