Igarashi's father Tsutomu was a surfer in Japan and a fan of the sport.

When his wife Misa found out she was pregnant, the couple quit their jobs in Tokyo and moved to Huntington Beach, California, aka Surf City, with the goal of raising their child to be a competitive surfer.

[5] As a top ranked finisher of the 2019 WSL CT, Igarashi qualified to compete in the 2020 Summer Olympic Games in Tokyo as a representative of Japan.

[9]In 2016, he was the youngest rookie on the World Surf League (WSL) Championship Tour (CT), and had collected more Round One wins than any other surfer, finished 2nd place at the Pipeline event, and 20th place overall that year.

[3] His greatest career performance was in the 2022 WSL CT where he finished top 5 and got to compete on the final event of the year held in Trestles California.