Born in Hikone, Shiga Prefecture, Kiryū played football while at elementary school and became interested in track and field at junior high school, as his brother took part in the sport.

[3] The following year, Kiryū ran in the under-18 category at the same competition and broke the world youth best for the 100 metres by bettering Tamunosiki Atorudibo's record of 10.23 seconds by two hundredths of a second on 5 October 2012.

[4] On 29 April 2013, Kiryū (still a student at Rakunan High School in Tō-ji)[5] ran at the Oda Memorial meet and tied the World junior record of 10.01 seconds co-held by Darrel Brown and Jeffery Demps.

The IAAF subsequently rejected the inclusion of the time as an official record due to the use of unapproved wind-speed measurement equipment on the track.

[6] At the 2016 Summer Olympics, Kiryū won a silver medal in the 4 × 100 metres relay.