Mamoru is a very rare boys' name that was most common in the 1920s and has all but disappeared.
Mamoru is a boy name. It last appears in U.S. records in 1937. Mamoru first appears in 1915 and peaked in 1924 (16 births).
| Year | U.S. births | U.S. + territories | Rank |
|---|---|---|---|
| 1937 | 5 | — | #3,843 |
| 1935 | 5 | — | #3,967 |
| 1932 | 11 | — | #2,409 |
| 1930 | 6 | — | #3,849 |
| 1929 | 6 | — | #3,807 |
| 1928 | 10 | — | #2,773 |
| 1927 | 11 | — | #2,633 |
| 1926 | 16 | — | #2,040 |
| 1925 | 14 | — | #2,274 |
| 1924 | 16 | — | #2,099 |
| 1923 | 10 | — | #2,874 |
| 1922 | 11 | — | #2,739 |
| 1921 | 11 | — | #2,736 |
| 1920 | 11 | — | #2,706 |
| 1919 | 11 | — | #2,607 |
| 1918 | 5 | — | #4,559 |
| 1917 | 9 | — | #2,872 |
| 1916 | 9 | — | #2,852 |
| 1915 | 5 | — | #4,173 |