Is this your first trip to Japan or Hakone? Do you have any other onsen ryokan stays on your trip? Did you plan on viewing the fall colors/leaves?

There are some mega-ryokans in Hakone which might offer overnight stay plans without dinner and only includes breakfast if you're mostly interested in Hakone sightseeing. You'd want to find one which will offer train station pickup later in the day, check the bus schedule to make sure it is still running in the evening, or take a taxi. If this is your first trip to Hakone and the only ryokan stay then I'd advise arriving early to enjoy the facilities & meals. It might also make sense to arrive in the daytime and go check out the fall leaves https://www.japan-guide.com/blog/koy...16_hakone.html and you'll want to have dinner included at the ryokan as finding an open standalone restaurant for dinner might be a little challenging without a car. OTOH, if you are planning some good meals elsewhere and aren't a fan of onsen or prefer to be "doing" rather than "relaxing" then look into a breakfast + room plan. You can forward your bags from Osaka/Kyoto to Tokyo via takkyubin and just pack an overnight bag.

Like evergrn, as an onsen aficionado, I typically stay put from check-in to check-out at onsen ryokan like most people treat an all-inclusive resort. Hakone is a convenient location and the ryokans are mostly first time foreigner friendly but to be honest, I haven't visited Hakone in many years as I prefer to explore smaller onsen areas with superior onsen water. I also find it better bang for the buck to go further from Tokyo. I might consider a later solo arrival with room + breakfast, no dinner plan if I was just going to see the fall colors the next day and splurging somewhere else. If I was traveling with others then it would be the traditional half board stay and arrive a bit after check-in opens or at latest, probably 5 pm.