Bukkō-ji (佛光寺 Bukkō-ji), also known as the "Temple of the Buddha's Light", was originally named Kosho-ji, a Jōdo Shinshū temple in the Yamashina ward of Kyoto, which later moved to the heart of Kyoto. The temple was founded and officially opened by a disciple named Ryōgen in 1324, but by the 15th century, Bukkō-ji was the largest and most successful temple, and its network of branch temples extending throughout the provinces of western Japan. As a rival to the Hongan-ji, it received much criticism for its evangelical practices from Kakunyo the head of the Hongan-ji. Around 1481, however, Bukkō-ji became a subordinate temple to the Hongan-ji. Many of the Bukkō-ji's congregation thus became members of the Hongan-ji, thus greatly reducing the stature.
While Bukkō-ji is technically an independent Jōdo Shinshū branch it has had close links to the Hongan-ji lineage since the time of Rennyo.
The founder of the Bukkō-ji temple, Ryōgen (了源 1295–1336), was a disciple of Jōdo Shinshū Buddhism in the Kantō region, but moved to Kyoto in 1320 in order to set up a small chapel in the Yamashina area of Yamashiro Province (now part of modern-day Kyoto). The head of the Hongan-ji at the time, Kakunyo, initially was receptive of the idea and gave it the name Kōshō-ji (興正寺). Further, Kakunyo instructed his son Zonkaku to administer to Ryōgen religious training and Hongan-ji textual documents. Zonkaku and Ryōgen developed a strong rapport with one another during this period, but by 1324 the tension between Zonkaku and his father, Kakunyo, had worsened to the point that Kakunyo disinherited his son and disassociated himself with Ryōgen due to differences in understanding Hōnen and Shinran's teachings. Thus, when Kosho-ji was established in 1324, it was not done so under the blessing of Hongan-ji. Zonkaku was a priest along with Ryōgen in the formative years of the temple, and assisted with presiding over certain yearly festivals and writing manuals and texts to use.