Adding the Garden to the hotel through the same door going to the hot springs. It will be there at the beginning and look like this.
A small event will show up, Lin will explain this location used to be a seating area, and grandpa had plans to grow food when money was tight in the back. But now that you aren't strapped for cash, you can turn this into anything you would like. After purchasing an upgrade, it looks like this.
I'm planning for Lin to hangout here instead of the utility room. This is where she does vineworking for her Midlari-Uneli (Or simply Midlari, AKA Wednesday) holiday. This is also where Lin will take Jin to craft Midlari vines in one of Jin's new events after she's taken off drugs.
I'm still working on the room back there, nothing to mention yet.