Cognomen 真一 (Zhenyi 
, 真一 ) , all over the world, is a rare last name. The cognomen 真一 is habitual in Taiwan, where it is a rare surname, Singapore, and Malaysia. Not in comparison with a country's population, it most frequently occurs in China, Taiwan, and Malaysia. More prevalently, 真一 is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Zhenyi | China, Malaysia, Singapore, Taiwan, United States |
| 真一 | China |
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香川 真一 Japanese politician, JP (b. 1835) |
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小松 真一 Japanese engineer (1911-1973), JP (b. 1911) |
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| 河端 真一 JP (b. 1951) |
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| 笠 真一 JP (b. 1952) |
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