Last name Kiyoi (Kiyoi 
) , throughout the world, is quite a common family name. The surname Kiyoi is characteristic of Japan, where it is quite a rare surname, Tanzania, where it is a very rare surname, and Indonesia. Not in comparison with a country's population, it is commonest in Japan, Indonesia, and the United States. Much less frequently, Kiyoi is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Kiyoi | Tanzania, China, Indonesia, United States, Japan |
| stephen kiyoi researcher (ORCID 0000-0001-7622-6995) |
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| hitoshi kiyoi researcher (ORCID 0000-0001-6382-9498) |
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| saki kiyoi Japanese talent (b. 1999) |
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