I Looked Into Tonosawa Ichinoyu Honkan

On this blog, I've been continuously looking into hot spring inns that could work as relaxing hotel-getaway spots—candidates for those times when I'm too tired from camping, or just don't have the energy to go camping at all. This time, I finally decided to dig into the Hakone area.

The reason is simple: as an indoor type, I just can't help being drawn to long-established, historic hot spring inns. This time I looked into Tonosawa Ichinoyu Honkan. Apparently it's an inn with a history going back to its founding in 1630, and the moment I saw the name, I got curious and started researching right away.

The Short Version

This looked like an inn with a lot of history—founded in 1630 and registered as a national Tangible Cultural Property—where you could relax in large baths and private baths along the gorge.
As for Rakuten Mobile signal, the official tool showed an AAA rating, which is a pretty solid result.

I've summarized the details below.

What Kind of Place Is Tonosawa Ichinoyu Honkan?

It's apparently a long-established inn located along the Hayakawa gorge in the Tonosawa area of Hakone, Kanagawa Prefecture. It's one of the properties run by the Ichinoyu group, built as a four-story wooden structure in sukiya-style architecture. It was also registered as a national Tangible Cultural Property in 2009, so the historic building itself seems to be one of the main draws.

While researching, I noticed that the name is written slightly differently across sources—sometimes with a space in a certain spot, sometimes without. Even on the official website, it seems to just be a matter of whether there's a space or not, and it refers to the same property either way, so it doesn't seem like something to worry about.

Apparently every room faces the gorge, so you'd be able to spend your time gazing at the Hayakawa River flowing by. However, due to the nature of the building, there's no elevator, and you need to use the stairs to get around, so I felt that's worth keeping in mind if you have a lot of luggage or are concerned about your legs and knees.

Komorin

Hearing 'founded in 1630' makes it feel like something out of a history textbook. Since I'm an indoor type, an inn where the building itself is a highlight like this makes me feel like I've already been there just by knowing about it.

Checking Out the Baths and In-House Facilities

There are apparently two large baths, called Kinsen no Yu and Megumi no Yu, which are available on a rotating basis for men and women. They're indoor baths rather than open-air ones, and it seems like a combination of circulating and flow-through hot spring water is used. They're open from 1 PM to 10 AM the next day, but not available between midnight and 5 AM, so it looks like a quick late-night soak isn't really an option.

What personally caught my attention was that there's a marble private family bath, imported from Italy in the sixth year of the Taisho era (1917), which is free to use. From 3 PM to 11 PM, you apparently need to reserve it same-day, first-come-first-served, at the front desk, but between 5 AM and 9 AM you can use it without a reservation. There also seem to be rooms with their own open-air baths or view baths, and since the facilities vary quite a bit depending on room type, it's probably worth double-checking that carefully when booking.

Another thing I found interesting is a service called yu-meguri, or "hot spring hopping." Apparently, both overnight guests and day-trip bathers can use the hot springs at other Ichinoyu group properties at no extra charge, just by showing their receipt or invoice. Since overnight guests seem to be able to use this from check-in day through check-out day, you could get the feel of visiting multiple hot springs without even staying multiple nights.

Day-trip bathing: apparently 1 PM to 8 PM (last entry 7:30 PM), 1,400 yen for adults and 700 yen for children
In-house facilities: there's apparently a fully automatic mahjong table (paid), go and shogi sets (free), and a free drink corner just for overnight guests
Meals: dinner is centered around Yonezawa beef shabu-shabu or sukiyaki, apparently with all-you-can-drink included. Breakfast seems to be a Japanese-style set meal served in three time slots
Wi-Fi: there's apparently free Wi-Fi throughout the building, though I couldn't confirm the details of availability in each individual room

Access and Booking Notes

If you're driving, it's apparently just a few kilometers from the Hakone-guchi interchange, but since I'm a license-holder who barely drives, I couldn't really picture myself driving there. If you're using public transportation, the route seems to involve taking a Hakone Tozan Bus shuttle, getting off at the nearest stop, and then walking about a minute from there. The bus fare is apparently around 200 yen for adults, so it seemed like a place that's easy to reach even without a car.

I couldn't find specific check-in and check-out times spelled out on the official website, but working backward from the dinner start time, it seems to be assumed that you'd finish checking in by 6 PM. Booking is apparently possible both online and by phone, and it also looks like you can book through several outside reservation sites. As for room rates, I couldn't find a clear price chart on the official website, so I'll refrain from listing specific figures in this article. Since prices also seem to differ from one booking site to another, it's probably best to check the latest information on each site when you actually book.

Rakuten Mobile Signal Conditions

When I checked this property's location using the official "My Area Connectivity Simulation" tool, the overall rating came back as "AAA." That's how it was displayed on the official tool, at least.

Since it's located along a gorge, some people might worry about signal strength, but based on what I checked this time, the results looked good, so this should be useful as a reference point for anyone using Rakuten Mobile who's considering a stay here.

Komorin

Being along a gorge naturally makes me a little worried about signal, but hearing about the AAA rating put my mind at ease a bit. With this, I don't think I'd need to worry about scrolling on my phone while relaxing at the inn.

See Rakuten Mobile Details

Wrapping Up

To sum it all up, Tonosawa Ichinoyu Honkan struck me as a long-established inn with a history stretching back to its founding in 1630 and its status as a national Tangible Cultural Property, where you could relax in large baths and a free private bath overlooking the gorge. The lack of an elevator and the fact that I couldn't pin down detailed pricing from the official website are things worth checking before booking, just to be safe.

As for Rakuten Mobile signal, the result came back as an AAA rating, but if you're curious, I'd recommend checking it yourself with the official Rakuten Mobile tool.

Check Out Rakuten Mobile

This article includes a referral link for Rakuten Mobile's employee referral campaign. For details, please see our Disclaimer & Advertising Notice.