Fukoji Temple, also known as Ajisai (Hydrangea) Temple, belongs to the Koyasan Shingon sect and is located on Mt Tsukushi.

Nichira founded the temple in 583. Known as Chikushioji at the time, the temple prospered during the Heian and Kamakura periods to become one of the three leading Holy Temples of Kyoto. The temple was demolished in 1586 in the battle of Hosatsu, but was restored in 1594 by the lord of Okajo Castle, Nakagawa Hisakiyo.

The impressive Magaibutsu sculptures carved in the rockface near the temple features the Fudo Myo-o (Acala) Buddha in the middle, accompanied by Seitaka and Kongara, and Tamonten (Chief of the Four Heavenly Kings) and Benzaiten (the goddess Sarasvati) to his right. The Fudo Myo-o is the largest Buddhist statue in Japan, measuring 11.4m high, the head alone being 2.4m.

Approximately 3000 hydrangeas in the temple precincts bloom around June. The annual Hydrangea Festival features a myriad of color and embellishes the land.