i have 3 suggestions, they probably would be hard to add but they could be cool <3
1) a gay bar/sauna/bath house. - Basically a place you can meet guys and then have a chance to become friends or fuck. becoming a friend with someone will allow you to bring them in battle 3 times, and if you have sex with someone you have a chance of getting gifts like a weapon. (Along with the sex scene). You could also just do this to the winners bar
2) a dating system (of sorts) - Basically if you have good relations with a character (not just from the bar) you can form a relationship with the characters, where you can ask them to come to your house and hook up, go on a date or on a visit to the pier etc. and each and every time you do an activity with a character you can get special items as well or just relax :)
3) A train station that connects smaller towns - The idea is that if you wanna add some new things to the city you could just create a smaller town accessible by train. I don't think you will add this since it requires creating whole new places, people monsters and a lot of other stuff.
let me know what you think! i doubt you have the time to add features like these but i would be very thankful if you did!