The screenshot shows the wording: "The more money ... the less likely the character will accept your gift."
I think you want to say "more likely to accept" or "less likely to reject".
I would also change "character" to "girl/boy".
Maybe you don't need two separate options, either. The first one alone is enough, with a 1000c default amount. Just a thought.
I would really love to see a story path that gets you a harem with all the main girls together. But that may be asking too much?
Edit for one more... I really like the study scene. I've thought in the past that you need to do more show, not tell. I hope in the future to see other scenes, too, like running, lesson time, movie time, and sand castle girl.
Here's an idea for you. How about add a bit of a panty shot, or more, if the girl's lewdness and trust in you is high?