I'm afraid that, just like in real life there are people who don't give second chances, if Moon's date failed, she won't want to go on a second date with you, so your only options are to go back to a day before the date or start a new game. The only thing I can advise you is that you start a second game, play it parallel to the game and, in addition to fixing things with Moon, make other decisions in the main story to play other routes, that will make your game less repetitive. I'm so sorry.
Oh that really sucks. I guess i'll have to start over again.
I have another question. Is starting a game club with Katsune a big responsibility? Joining the gardening club was a bit overwhelming for me with the daily flower-watering. I would prefer to join a club that's low maintanence. So is creating the gaming club the best option for me? Or do you recommend another club?