Kaminoyama Onsen is surrounded on Kaminoyama Onsen sides by mountains such as the Zao mountain range, and retains the atmosphere of a castle town and post town. Koyo is known for its particularly elegant facilities and the flawless hospitality of the entire staff, from the proprietress down. You will be welcomed into a heartwarming space decorated with flowers and trees. You will also be captivated by the Raku ware gallery, which displays over 3,000 Raku ware pieces by famous people from various fields. It is a space where the wishes of the creators and the inn's wishes for good relationships with its guests overlap. Be sure to try making your own Raku ware in the experience corner. If you make it while thinking of someone important to you, it can also be a heartfelt gift.

From standard Japanese-style rooms and Western-style rooms to rooms with open-air baths and VIP rooms, the hotel offers a range of rooms equipped with both Japanese comfort and Western functionality. The fully renovated "Snow House" rooms with open-air baths are particularly popular. There are 26 "semi-open-air bath rooms" on the 4th to 6th floors, and 4 "open-air bath rooms" on the 6th floor that use hot spring water. All rooms are snow-themed and offer a relaxing space, equipped with Simmons beds that guarantee a deep sleep. You can also request a room with a view of the Zao mountain range, the most scenic spot in the area. The hotel also has an amenity station where you can freely choose the amenities you need from the perspective of the SDGs.

The "Premium Suite Room with Tea House Open-Air Bath" reopened in March 2023. In addition to an open-air bath where you can fully enjoy Kaminoyama Onsen, which has excellent skin-beautifying effects, this is Koyo's most luxurious suite room, which also includes a private sauna where up to five people can enjoy self-loyly, and a dedicated theater room where you can enjoy VOD on an 85-inch TV. You can turn the adjacent indoor bath into a cold bath and enjoy an open-air bath on the outdoor deck to rejuvenate your body. The synergistic effect of the hot spring, which is rich in metasilicic acid, will refresh both your skin and your mood. In the theater room, you can also enjoy your favorite content on video-on-demand such as Netflix and Hulu.
The best part of a hot spring is the dynamic view. On the eighth floor, you can enjoy the exceptional comfort of the open-air observation bath "Zao Garden," which offers a spectacular view of the Zao mountain range and the night view of Kaminoyama, and the large observation bath, which overlooks the cityscape surrounding Kaminoyama Castle's castle tower. Everyone is amazed by "Zao Garden." Stretching out your limbs and admiring the vast sky and mountain scenery is incredibly clear and you will be overwhelmed by the sense of openness. On the first floor, there is the "Safflower Bath," which features an open-air barrel bath with a Japanese atmosphere, a cold and hot "Kamakura Sauna," and a high-temperature sauna.

Depending on the plan, dinner can be enjoyed in a guest room, a stylish, modern private room, a private room overlooking the Japanese garden, or at the restaurant banquet hall, where you can enjoy the "best Michinoku delicacies." The latest menu is a new style of Japanese banquet called "Yui," where you can enjoy the marriage of eight carefully selected seasonal ingredients from Yamagata and eight sauces that best match each ingredient. You can enjoy melt-in-your-mouth Yonezawa beef and mellow Yamagata beef with just the right amount of marbled meat as steak or sukiyaki. The rice is "Tsuyahime," which is perfect in terms of whiteness, shine, and sweetness. The vegetables are grown by contracted farmer "Hyakushoen," and have the taste of the earth. You can also experience the powerful flavor of vegetables grown organically and with reduced pesticides. The special "Kama Pudding" made by the in-house pastry chef is a masterpiece made with eggs from local chickens in Zao. It is also a popular souvenir.
Breakfast is a buffet of 54 items including freshly picked vegetables and Yamagata delicacies, providing energy for the day. The freshness of the vegetables, which are served within a few hours of being picked, is particularly noteworthy. The inn's thoughtfulness is apparent in each and every colorful flavor. The staff, who speak the local dialect, are attentive to your needs and will serve you with a smile. The nostalgia for Yamagata that can be felt everywhere will gently fill your heart.