Kayzen is a modern American respelling of kaizen, the Japanese word for "continuous improvement" or "change for the better" that became famous as a business philosophy, reshaped to look like a brother of Kayson and Kaysen. The z gives it the edge that many parents now look for in boys' names. Kayzen had fewer than five births in 2000, jumped from number 7035 in 2022 to number 3944 in 2023 and reaches its best rank in 2025 at number 2909 with 43 births.