Saicho (767–822) is often called the ‘mother of Japanese Buddhism.’ After traveling to Tang China in 804 and studying Tiantai teachings on Mt. Tiantai, he returned to Japan and established Tendai Buddhism at Enryakuji on Mt. Hiei. Remarkably, all the great founders of Kamakura Buddhism — Honen (Pure Land), Shinran (Jodo Shinshu), Dogen (Soto Zen), and Nichiren (Nichiren Buddhism) — trained on Mt. Hiei before establishing their own schools. Saicho’s core teaching was the Lotus Sutra’s ‘one-vehicle’ doctrine: that every being has the potential to become a Buddha. His famous saying, ‘Illuminate one corner — that is the national treasure,’ reflects his ideal of modest, sincere devotion. Visitors can experience his legacy at Enryakuji, a UNESCO World Heritage Site, where the eternal flame he lit over 1,200 years ago still burns in the Konpon Chudo hall.