Ryugujo Spa Hotel Mikazuki Kisarazu: Day-Use Hot Spring

Built facing Tokyo Bay in Kisarazu, this is one of the largest spa resorts in the Kanto region. There are indoor large baths and outdoor baths for both men and women, where you can soak while looking out over Tokyo Bay and, on clear days, Mount Fuji. It is easy to reach by car from the city center and is popular with families.

Highlights

The standout feature is the large bathing area with many different types of baths. There is also a pool you can enjoy in swimwear and a variety of spa zones, making it a volume of attractions hard to cover in a single day. Using natural hot spring water welling up from about 800 meters underground on site, the outdoor bath set against Tokyo Bay lets you watch the ships passing along the Aqua-Line.

Enjoying the Seasons

In summer you can enjoy both the pool and the hot spring, and in winter you can take in the night view of Tokyo Bay from the steaming outdoor bath. From the clear-skied autumn through winter, the chances of seeing Mount Fuji rise as well.

Access and Basic Information

The address is 1 Kitahama, Kisarazu City, Chiba. It is about five minutes by car from the Kisarazu-Kaneda interchange of the Tateyama Expressway and Aqua-Line connector road, and roughly fifteen minutes by car from Kisarazu Station. Day-use is possible, with hours generally from 10:00 to 21:00, and until 22:00 on weekends and holidays. Admission is around 1,000 yen for a one-day pass for both adults and children, following a fee revision in June 2026. Day-use spa visitors get free parking for up to five hours. There are scheduled maintenance closures, so confirm the operating days and fees on the official site before you visit.

Practical Travel Notes

To fully enjoy the pool and spa zones, arriving at the 10:00 opening for a full day is ideal. A personal locker key lets you come and go until closing, so you can take breaks and spend the day at a relaxed pace. Budget about a thousand yen for day-use admission for an adult, with meals or extra-charge spa options still reasonable. Days ending in three may feature special Mikazuki Day events. Close to the city center via the Aqua-Line, it pairs easily with Umihotaru, the outlets, and sightseeing around Kisarazu. If you are after the night view, arriving from late afternoon is recommended.

A Quick Tip

A great plan is to combine the evening light-up of the Aqua-Line with the outdoor bath. Enjoying the night view while staying warm gives you a scene unique to Tokyo Bay. For families the daytime pool works well, and for adults alone the evening outdoor bath, so the facility shows a different face depending on the hour.

Practical Information for Your Visit

• Hot spring name and quality: Kisarazu Onsen, a sodium chloride strong salt spring. According to the hotel's guidance, the water rises naturally from 800 m underground on the site, and its benefits are joint pain, recovery from fatigue and chronic digestive disorders
• Suspension of the hot spring supply: From March 20, 2026 and until further notice, the hot spring supply to some of the tubs in the large bathhouse has been suspended for emergency maintenance. There is no set date for resumption
• Open-air bath: There is a large stone-built open-air bath called "Kangetsu." It may close at short notice depending on the weather
• Day-use opening hours: According to the listing on the official Chiba Prefecture tourism site, 10:00-21:00 on weekdays (last admission 20:00) and 10:00-22:00 on Saturdays, Sundays and public holidays (last admission 21:00). Maintenance closure days are sometimes scheduled, so check together with the opening hours table on the official website
• Day-use admission: On weekdays, 2,000 yen for adults, 1,300 yen for children (age 4 through sixth grade of elementary school) and 1,500 yen for seniors (65 and over). On Saturdays, Sundays and public holidays, 2,600 yen for adults (junior high school age and above) and 1,800 yen for children
• Bargain weekdays: Days containing the number 3 are "Mikazuki DAY," when both adults and children pay 1,000 yen for a 1DAY ticket. On "Special DAY," adults pay 1,500 yen instead of 2,000 yen and children 1,000 yen instead of 1,300 yen (towel set included). On Ladies' DAY on Wednesdays and Men's DAY on Thursdays, you receive a 500 yen discount voucher for your next visit
• Rentals: Towel set 550 yen, in-house wear 220 yen, swimsuit 1,100 yen, swim ring 550 yen (1 hour) or 1,100 yen (all day)
• Start of use for overnight guests: Overnight guests may use the facilities from 11:00 after checking in at the hotel front desk
• Parking: 1,200 spaces for passenger cars and 50 for large buses. Free for overnight guests; for day visitors it is free for up to 5 hours and 400 yen for each subsequent hour
• Access (by car): About 5 minutes from the Kisarazu-Kaneda IC on the Tokyo Bay Aqua-Line Connecting Road
• Access (by rail and bus): A free shuttle bus from Kisarazu Station on the JR Uchibo Line. By highway bus, get off at the Kisarazu Kaneda Bus Terminal, from where a free shuttle bus also runs. More than 100 highway buses a day arrive at and depart from that terminal. Note that the shuttle bus does not run on closure days
• Location and inquiries: 1 Kitahama-cho, Kisarazu City, Chiba Prefecture, telephone 0438-41-8111
• Time needed: 1-2 hours for bathing alone. If you also want to take in the pools and spa zone, plan on a full day starting right after opening

📚 Sources

The notice about the suspension of the hot spring supply (from March 20, 2026 until further notice, with no set date for resumption), the make-up of the baths, the weather-related closures of the large stone-built open-air bath "Kangetsu," the day-use parking charges (free for up to 5 hours, then 400 yen per hour), rental prices, the details of the weekday discount events and the start time for overnight guests were confirmed on the news section and the "Baths and Leisure" pages of the official Ryugujo Spa / Hotel Mikazuki website. Access details (the Kisarazu-Kaneda IC, the free shuttle buses from Kisarazu Station and the Kisarazu Kaneda Bus Terminal, and the absence of service on closure days) come from the access page of the same official site. The address, telephone number, day-use opening hours, admission fees and number of parking spaces are from the facility information on the official Chiba Prefecture tourism site "Chiba Kanko Navi," while the hot spring name, spring quality, natural flow from 800 m underground and benefits are compiled from the hot spring information published by the hotel. Details are subject to change, so please check official information before you set out.