Rokuouin (officially known as Kakuyuzan Daifukuden Hōzō Zenji Rokuouin) is a Rinzai Zen temple founded by Ashikaga Yoshimitsu in 1379, during the first year of the Kōryaku era. Yoshimitsu was moved to establish the temple after a dream in which he heard Tamonten and Jizō Bodhisattva discussing how building a temple would extend his life. The founding abbot was Shun'oku Myōha, and the temple was initially named "Kakuyuzan Daifukuden Hōzō Zenji."
The temple was established as the principal pagoda of Hōzō-ji Temple. The name "Rokuouin" is inspired by an event where a herd of deer appeared, as well as the legendary Deer King from the Deer Park, where Buddha gave his first sermon. As the only affiliated sub-temple of Hōzō-ji, Rokuouin held significant influence within the Shun'oku school. It had the authority to recommend the abbot of Hōzō-ji to the shogunate and to manage the appointment and dismissal of abbots for its 15 branch temples. The temple also oversaw various estates scattered across the country.
Rokuouin and Hōzō-ji saw their peak prosperity from the late 15th to the early 16th century, with visits from a succession of shoguns, including Yoshimitsu, Yoshimochi, Yoshinori, and Yoshimasa. However, the entire Saga area was devastated by the fires of the Ōnin and Bunmei conflicts in 1468. While Hōzō-ji was never rebuilt, Rokuouin was restored and continues to uphold the legacy and formal status that once belonged to Hōzō-ji.