Takashi Nagai was a Japanese Catholic convert, doctor, and survivor of the atomic bombing of Nagasaki, who became a powerful witness to faith and peace. Born in 1908, he studied medicine and radiology at Nagasaki Medical College, where he was influenced by Catholic professors and ultimately converted to Christianity in 1934. He married Midori Moriyama, a devout Catholic, and together they lived a life of deep faith. As a doctor, he specialized in radiology but was later diagnosed with leukemia due to prolonged radiation exposure from his medical work.

On August 9, 1945, Nagai was working at a hospital when the atomic bomb devastated Nagasaki, killing his wife and countless others. Though severely injured, he dedicated himself to treating survivors and chronicling the horrors of the bombing. Confined to bed in his final years, he wrote extensively on faith, suffering, and reconciliation, producing works such as The Bells of Nagasaki, which became a symbol of hope and healing. Despite his immense suffering, he remained steadfast in his belief in God’s providence and the necessity of forgiveness.

Nagai spent his remaining years in prayer and writing from his simple hut, known as "Nyokodō" (The Hut of Love for Others). His testimony of faith and perseverance inspired many, earning him the nickname "the Saint of Urakami." He died in 1951 at the age of 43, leaving behind a legacy of faith, peace, and resilience. Today, he is remembered as a model of Christian charity and a voice for peace in the aftermath of war.