He attended the University of Tokyo, and upon graduation joined the staff of the literary magazine Shin-Shicho (新思潮: "New Thought") in 1950.

[1] He then married fellow Third Generation writer Ayako Sono in 1953, with whom he wrote many books about Catholicism and religion.

Miura began teaching at Nihon University in 1967, the same year he was awarded the Shinchosha Prize.

In 1999, the Japanese government designated Miura a Person of Cultural Merit.

He stepped down in 2014, and died at a hospital in Tokyo due to pneumonia on 3 February 2017, aged 91.