Yeah I looked up the hours and transportation option, there are ways to get there.
But I'm more interested in whether it's worth the trip, I've not been to a large public onsen so in terms of the quality of the facility and food offers there, given the surcharge for overnight stay. Is everything open overnight within the complex?
Also would the lockers be large enough for a carryon suitcase?
The baths are open all night but many of the other amenities close.