Koichi is a very rare boys' name that was most common in the 1920s and has all but disappeared.
Koichi is a boy name. It last appears in U.S. records in 2007. Koichi first appears in 1914 and peaked in 1921 (16 births).
| Year | U.S. births | U.S. + territories | Rank |
|---|---|---|---|
| 2007 | 5 | 5 | #13,509 |
| 1994 | 5 | — | #9,627 |
| 1988 | 6 | — | #6,884 |
| 1930 | 6 | — | #3,815 |
| 1929 | 5 | — | #4,296 |
| 1927 | 8 | — | #3,311 |
| 1926 | 6 | — | #3,977 |
| 1925 | 6 | — | #3,975 |
| 1924 | 11 | — | #2,749 |
| 1923 | 12 | — | #2,532 |
| 1922 | 9 | — | #3,137 |
| 1921 | 16 | — | #2,110 |
| 1920 | 8 | — | #3,363 |
| 1919 | 12 | — | #2,435 |
| 1918 | 12 | — | #2,470 |
| 1917 | 8 | — | #3,070 |
| 1916 | 5 | — | #4,229 |
| 1914 | 5 | — | #3,523 |