Kōsan-ji Temple, Buddhist temple in Onomichi, Japan

Kōsan-ji is a Buddhist temple on Ikuchijima Island that spans a large area with multiple buildings displaying different styles of Japanese architecture. The complex includes various structures and houses a museum with classical Japanese art pieces.

Construction began in the 1930s when a businessman initiated the project as a personal memorial, and the work took several decades to finish. The site today shows different architectural layers that reflect this long building period.

The temple is nicknamed "Mother's Temple" because Kōzō Kanamoto, who took the name Kōsanji Kōzō, became a monk in 1935 after his mother's death and built the complex in her memory. The Kōyō Gate, modelled on the Yōmeimon at Nikkō Tōshōgū, is said to have been made more colourful than its model because he wanted to dress his mother beautifully. The temple is affiliated with the Jōdo Shinshū Hongan-ji school and has no parishioner families.

Access is by car from the Setouchi Expressway's Ikuchijima North or South interchange, about ten minutes toward Setoda, or by boat to Setoda Port from Mihara (25 minutes), Onomichi (35 minutes) or Sawa Port (20 minutes). The grounds climb in terraces from the main gate up to the Hill of Hope, so allow time for the stairs. The temple is open daily from 9 to 17.

A hilltop within the grounds features a collection of sculptures made from Italian marble, including a tower structure at its peak. This unexpected European art presence creates a striking contrast with the traditional Japanese buildings.