Born in Chiba Prefecture in 1988.He started making dresses at 14 years old and learned by self-taught.
Koizumi launched his brand TOMO KOIZUMI in 2011 while he was in university.His first fashion show was presented in 2019 at New York Fashion Week.In the same year, He was selected for BoF500.In 2020, he was awarded the LVMH Prize 2020 as one of the eight recipients.At the opening ceremony of the Tokyo Olympics 2020, he was in charge of the costume for the national anthem singer. In 2021, he won the Grand Prize of the Mainichi Fashion Grand Prix which means he took first place for a Japanese fashion designer in this year.In 2023, he presented his collection at Milan Fashion Week supported by Dolce&Gabbana.
While working as a dress designer, he will also begin making contemporary art as a studio artist in 2022. He held his first solo exhibition, "Tomo Koizumi," in December 2023, and continues to expand the scope of his activities.