2000
#119,644
National surname rank
Recorded bearers 134
First available Census row
Per 100,000 0.05
Very Rare Last name
Kajioka
A Japanese surname potentially derived from a place name or occupation.
According to the 2020 US Census Bureau surname tables, roughly 139 Americans carry the last name Kajioka. That puts it at #141,309 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,465,859 residents).
This page is the full Name Census profile for the Kajioka surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
Bearers in the US
139
1 in 2,465,859
Census rank
#141,309
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
121
very rare in the US
Popularity narrative
The Census Bureau recorded 121 bearers of the surname Kajioka in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 141309th position in the national surname ranking.
Among Census respondents with the surname Kajioka, the largest self-reported group is Asian/Pacific Islander at 76.9%. The next largest groups are White (10.7%) and Two or More Races (7.4%).
Origin
Meaning and origin of Kajioka
The surname Kajioka originates from Japan, where it first emerged during the Kamakura period between 1185-1333 AD. The name likely has roots in the Kajioka region of the present-day Gunma Prefecture, suggesting a connection to a specific geographic location.
One of the earliest recorded mentions of the Kajioka surname can be found in the Kamakura Bakufu records from the late 13th century. These records document various samurai clans and their landholdings, indicating that the Kajioka family may have been a prominent samurai lineage during this time.
During the Muromachi period (1336-1573), the Kajioka name appears in several historical texts, including the Taiheiki, which chronicles the civil wars of the 14th century. This suggests that members of the Kajioka clan were likely involved in the political and military affairs of the era.
In the Edo period (1603-1868), a notable Kajioka figure was Kajioka Masataka (1650-1721), a renowned scholar and poet who served as a retainer to the Tokugawa shogunate. His literary works and contributions to the development of Japanese poetry have been widely recognized and studied.
Another influential individual bearing the Kajioka surname was Kajioka Yoshiaki (1785-1855), a prominent feudal lord and daimyo who ruled over the Tosa Domain (present-day Kochi Prefecture) during the late Edo period. He played a significant role in the governance and economic development of the region.
During the Meiji era (1868-1912), Kajioka Kunitaro (1831-1899) was a prominent figure in the field of education. He founded the Kajioka Gakuen, a private school that aimed to promote Western-style education and contributed to the modernization efforts of Japan in the late 19th century.
The Kajioka surname has also been associated with various other fields, including business, politics, and the arts, throughout Japanese history. While the name's origins can be traced back to the Kamakura period, it has maintained its presence and significance across different eras and regions of Japan.
Demographics
Ancestry and ethnicity for Kajioka
Among Census respondents with the surname Kajioka, the largest self-reported group is Asian/Pacific Islander at 76.9%. The next largest groups are White (10.7%) and Two or More Races (7.4%).
The bar chart below shows how Kajioka bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Kajioka surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander76.9% · 93
- White10.7% · 13
- Two or more races7.4% · 9
- Hispanic or Latino5.0% · 6
Timeline
Historical Census data for Kajioka
Kajioka appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#123,064
National surname rank
Recorded bearers 140
+6 bearers (+4.5%)
Per 100,000 0.05
Rank movement Down 3,420 places
2020
#141,309
National surname rank
Recorded bearers 121
-19 bearers (-13.6%)
Per 100,000 0.04
Rank movement Down 18,245 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #119,644 | 134 | 0.05 | First available Census row | First available Census row |
| 2010 | #123,064 | 140 | 0.05 | +6 bearers (+4.5%) | Down 3,420 places |
| 2020 | #141,309 | 121 | 0.04 | -19 bearers (-13.6%) | Down 18,245 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Kajioka surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #123,064 | #141,309 | -14.8% |
| Count | 140 | 121 | -13.6% |
| Per 100K | 0.05 | 0.04 | -19.0% |
Between the 2010 and 2020 Census, the number of Kajioka bearers went from 140 to 121 (-13.6% change). The surname moved down 18,245 positions in the national ranking, going from #123,064 to #141,309.
FAQ
Kajioka surname: questions and answers
How many people in the U.S. have the surname Kajioka?
Name Census estimates that about 139 living Americans carry the surname Kajioka. Using the current population baseline, that works out to roughly 1 in 2,465,859 residents.
How common is Kajioka?
Kajioka ranks #141,309 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.04 per 100,000 residents, which is about 0 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 121 people with the surname Kajioka. That is different from the site's living-bearer estimate (139), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.04 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.04 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 0 of them to have the surname Kajioka.
Has Kajioka become more or less common over time?
Between 2010 and 2020, the surname Kajioka went from 140 recorded bearers to 121. That is a decrease of 19 (-13.6%). In the national ranking it fell from #123,064 to #141,309.
What does the Census say about the background of Kajioka?
Among Census respondents with the surname Kajioka, the largest self-reported group is Asian/Pacific Islander at 76.9%. The next largest groups are White (10.7%) and Two or More Races (7.4%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
Asian/Pacific Islander is the largest self-reported group for the surname Kajioka in the 2020 Census, accounting for 76.9% (93 people in the source table).
What is the full ancestry breakdown?
Kajioka appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (76.9%), White (10.7%), Two or More Races (7.4%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Kajioka (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Kajioka mean?
A Japanese surname potentially derived from a place name or occupation. The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Kajioka (0.04 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How many Americans have the surname Kajioka?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.