[1] His father, musician Kazufumi Miyazawa is Japanese and his mother, TV personality Dionne Mitsuoka is half-American, which makes him a quarter American.

His first acting role was in the TBS drama Dr.Storks (Kōnodori) in 2017, as the new intern in the Obstetrics and Gynecology Department of Persona General Medical Center.

He got his first lead role in the NHK drama R134/The Promise at Shounan and was filmed in Yokohama, his mother's hometown.

[3] 26 April, two days after his 25th birthday, it was announced that he will be playing the role of Jyo Banno in the drama adaptation of Gisou Furin by Akiko Higashimura.

On January 16, 2024, Miyazawa announced through his official website that he is expecting his first child with actress Kuroshima Yuina.