The Temple’s Origins and Its Connection with Kusatsu Onsen
According to temple tradition, Kosenji traces its origins to 721, when the renowned Nara-period Buddhist monk Gyoki is said to have established a Yakushi-do hall here.
Gyoki was a prominent monk known for his work helping ordinary people throughout Japan. According to the tradition surrounding Kosenji, he discovered the sacred spring waters of Kusatsu and recognized their healing qualities. He is said to have enshrined Yakushi Nyorai, the Buddha of Healing, at the site.
In 1200, the temple was rebuilt by the Yumoto family, the local rulers of Kusatsu, and became the Buddhist temple associated with Shirane Myojin. Kosenji subsequently developed an important religious and political role in the area.
The temple was granted the position of local estate administrator by the Kamakura shogunate and was also given temple lands in Shirane Manor, further strengthening its influence in the region.
From the Northern and Southern Courts to the Warring States Period
Following the fall of the Kamakura shogunate, Kosenji is traditionally said to have supported the Southern Court and sent warrior monks into battle.
Records remain of votive talismans associated with important Southern Court figures, including Prince Moriyoshi, Nitta Yoshisada, Kusunoki Masashige, Nawa Nagatoshi, and Kitabatake Chikafusa. These historical connections provide a glimpse into the turbulent political environment of medieval Japan.
In 1481, through the mediation of Konoe Michioki, Kosenji became an imperial prayer temple. It subsequently received an imperial plaque from Emperor Go-Hanazono and a handwritten document associated with Emperor Kashiwarabara.
During the Warring States period, the temple was also involved in the Battle of Sarugakyo and received a letter of commendation from Uesugi Terutora, later known as Uesugi Kenshin. These episodes demonstrate the temple’s connections with the military and political world of medieval Japan.
The Main Hall and Other Historic Buildings
Main Hall and Yakushi Nyorai
The main hall enshrines Yakushi Nyorai, the Buddha traditionally associated with healing and the relief of suffering.
This religious tradition has a particularly strong connection with Kusatsu’s hot spring culture. For centuries, people have traveled to Kusatsu for hot spring treatments, and Kosenji became a place where visitors could seek both physical healing through the hot springs and spiritual comfort through Buddhist faith.
Shakado Hall and the “Late-Blooming Buddha”
Shakado Hall was built in 1703 through the initiative of Gedo Genka Sosho, a physician from Edo, present-day Tokyo. It is a valuable surviving example of historic architecture within the temple grounds.
The principal image of Shakado is a statue of Shaka Nyorai, the historical Buddha, traditionally attributed to the monk Kokei of Todaiji Temple in Nara. According to its history, the statue was made using wood associated with the reconstruction of the Great Buddha of Todaiji.
A survey conducted in 2005 helped substantiate the historical tradition surrounding the statue. Because its story became widely recognized only after approximately three centuries, it came to be known as the “Late-Blooming Buddha.” The statue has since attracted renewed interest and devotion.
Five-Story Pagoda
A new five-story pagoda was completed in November 2023, creating a new symbol of Yakushi worship at Kosenji.
The pagoda stands approximately 21.4 meters high and features a striking vermilion exterior with titanium roofing. Yakushi Nyorai is enshrined here at an elevation associated with the wordplay “ii yakushi,” meaning “good medicine,” corresponding to an elevation of approximately 1,189.4 meters.
Sanmon Gate and Nio Guardians
The temple’s Sanmon gate is guarded by two imposing Nio statues, the traditional Buddhist guardian figures known as Agyo and Ungyo.
Their powerful forms provide a dramatic entrance to the temple and reinforce the solemn atmosphere of this historic place of worship.
A Symbol of Hot Spring Faith and Healing Culture
One of Japan’s Three Great Hot Spring Yakushi Temples
Kosenji is traditionally counted among the “Three Great Hot Spring Yakushi” temples in Japan, alongside temples associated with other famous hot spring resorts such as Arima Onsen.
The temple represents the longstanding connection between Japanese hot spring culture and Buddhist beliefs about healing. For generations, visitors coming to Kusatsu for therapeutic bathing also found spiritual comfort and a place for prayer at Kosenji.
Yua-mi Benzaiten and the Spring of Compassion
Within the temple grounds is a pond known as the Spring of Compassion, where Yua-mi Benzaiten is enshrined.
Benzaiten is a Buddhist deity associated with music, eloquence, wisdom, and fortune. At Kosenji, the deity has been regarded as a symbol of gratitude and joy associated with bathing in Kusatsu’s healing waters.
Memorial Tower for Those Who Died While Bathing
A memorial tower for those who died while bathing was erected in 1905. It commemorates people who died while undergoing hot spring treatment in Kusatsu, with the tradition extending back to the time when Minamoto no Yoritomo is said to have visited the springs.
The monument quietly conveys the long history of Kusatsu as a destination for hot spring treatment and reminds visitors of the many people whose lives were connected with the resort over the centuries.
A Temple Connected with Artists and Literary Figures
Kosenji has also attracted writers, poets, and other cultural figures over the centuries.
Konoe Ryuzan is said to have presented ten waka poems to the Yakushi-do during a stay in Kusatsu for hot spring treatment. His calligraphy is associated with the Konoe school of Japanese calligraphy.
The temple grounds also feature a monument commemorating the haiku poet Murakoshi Kaseki and a tanka monument dedicated to poet Yoshino Hideo. These monuments add a literary dimension to the temple and reflect the long tradition of artists and writers visiting hot spring resorts in Japan.
Annual Events and Kosenji Today
Traditional events continue to be held at Kosenji throughout the year. These include the Flower Festival and Benzaiten opening ceremony on May 7 and 8, as well as the Segaki memorial service held on August 16.
Kosenji has also appeared on Japanese national television. On New Year’s Eve in 2018 and 2022, the temple was featured as a location for NHK’s annual “Yuku Toshi Kuru Toshi” broadcast, which introduces New Year’s Eve scenes from locations throughout Japan.
A Temple Reflecting the Spirit of Kusatsu
Kosenji is much more than a sightseeing stop. For more than a thousand years, it has been closely associated with the history of Kusatsu Onsen, its hot spring treatment traditions, and the prayers of the people who have visited the area.
From the elevated temple grounds, visitors can look down toward Yubatake and see steam rising from the hot spring town below. The contrast between the lively resort and the quiet temple grounds creates a peaceful atmosphere.
For travelers exploring Kusatsu Onsen, a visit to Kosenji Temple offers an opportunity to look beyond the hot spring baths and discover the religious traditions and history that have developed alongside them.