My family of 4 enjoyed a few hours at this onsen earlier this week. My youngest daughter loves hot baths/hot tubs and thought it would be fun. Yet my older daughter absolutely did not want to be naked in front of strangers. Since my younger one really wanted to try it, she did a ton of research on-line and searched for onsen within 30 minutes of where we were staying in Tokyo, with outdoor and private onsen, and well-rated. She found this onsen (which has a great website with photos and lots of English explanations of the protocol), so I made a reservation via email. I booked a multiple course lunch and a private onsen room. Regular public admission doesn't require reservations. Note that I emailed three times before receiving confirmation. Not sure what happened as they said they had emailed earlier, but nothing was in my in box or spam filter.
My older daughter used the private onsen room for one hour while the 3 of us went to the public baths (my husband was alone on the male side).
We don't speak any English but were briefly checked in by an English-speaking woman. This was after we walked in and saw rows of shoe lockers. No English signage there but we figured out from watching other guests that we had to be barefoot and store shoes there (for 100 yen per locker). I thought they would offer slippers but they didn't. I also managed to put my 10 year old's sandals in the same locker as my shoes while my husband put our 13 year old's shoes with his, thinking we'd just save 100 yen. But after we checked in, she sent me back to pay for another shoe locker as each "adult" needs their own shoe locker key on an stretchy wrist bracelet. So I put in 100 yen for an empty locker. NOTE: they return the 100 yen when you return the key, which surprised me as the coin just rolls out of the slot!
After we put our shoes away, we walked into the main building to "check in." Once the English-speaking woman let us rent towels, she left with my older daughter to take her to the private onsen. Then the rest of us were left trying to figure out where to go. I ended up following some ladies into the ladies' side while he followed some men.
I deducted a star as more guidance for non-Japanese speakers would make this an outstanding experience. Since phones are not allowed inside once folks are naked, I couldn't use Google Translate on any of the signs. I had no idea what any of them said. I also saw today, from reviews here, that others received an English brochure--we never got one. Offering more guidance to non-Japanese guests would have made this a 5 star experience.
Once inside the women's section, I looked to others and copied their actions (e.g., disrobe, store clothing/phone/purse in locker, put shoe locker key bracelet inside and just keep general locker bracelet on your wrist--I had both bracelets on until I saw others only had one bracelet--sit on stool and wash before entering any baths, splash self with lukewarm water and then cold water at the end before you leave to put on clothes again).
I enjoyed all the outdoor baths the most. The indoor baths had sliding glass floor-to-ceiling windows and bubbles (like a hot tub), but they weren't as charming as the outdoor ones. I only spent about an hour in the baths, as I knew my teen daughter only had her room for an hour. I could likely have spent 2 hours there, as it was very peaceful and relaxing. The soothing heat helped relax some tense back muscles!
Afterward, the four of has a lovely multiple course lunch in the Sakura room (which you can reserve ahead of time via email). It was visually stunning and tasty, but SO MUCH FOOD. We actually had to request an end to the meal as we couldn't even finish what was before us. I don't know how much food was left but it was way too much for even hearty American appetites!
I believe we had several beautifully composed vegetable dishes, shabu shabu (each guest had their own delightful soup basin over a flame to cook meat and vegetables into), tempura, soba, and more! The serving staff were very attentive and detail-oriented. The man kindly showed us the handy iPad interface to order beverages and call for staff.
When you leave, you scan your shoe locker bracelets at an ATM-like machine near the exit and then pay. I think our final bill was around 32,000 yen, which was a great value given the multi-course gourmet lunch for 4 (6,000 yen per person and we had 4 people so no room rental fee for the Sakura Room), private onsen for one hour (2,000 yen), general admission (1100 yen per adult on weekends/holidays, discounted price for elementary school kids of 750 yen) and 4 towel set rentals (310 yen per towel set).
I highly recommend this experience. You may be the only foreigners, but it's a special treat.