2000
#134,037
National surname rank
Recorded bearers 116
First available Census row
Per 100,000 0.04
Very Rare Last name
Kumasaka
An uncommon Japanese surname possibly meaning "bear's slope" or "bear's hill."
According to the 2020 US Census Bureau surname tables, roughly 123 Americans carry the last name Kumasaka. That puts it at #151,639 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,786,621 residents).
This page is the full Name Census profile for the Kumasaka 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
123
1 in 2,786,621
Census rank
#151,639
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
107
very rare in the US
Popularity narrative
The Census Bureau recorded 107 bearers of the surname Kumasaka in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 151639th position in the national surname ranking.
Among Census respondents with the surname Kumasaka, the largest self-reported group is Asian/Pacific Islander at 66.4%. The next largest groups are Two or More Races (20.6%) and White (9.3%).
Origin
Meaning and origin of Kumasaka
The surname Kumasaka has its origins in Japan, dating back several centuries. It is believed to have derived from the combination of two older Japanese words, "kuma" meaning bear and "saka" meaning hill or slope, potentially referring to a geographic location associated with bears or a bear-like topography.
The earliest known records of the Kumasaka name can be traced back to the late 16th century, with mentions in local administrative documents and historical texts from the Kyoto region. One notable individual was Kumasaka Nobutoki, a minor samurai lord who lived during the Azuchi-Momoyama period (1573-1603).
In the 17th century, the Kumasaka family gained prominence as skilled artisans and craftsmen. Kumasaka Kiyonaga (1615-1682) was a renowned lacquerware artist whose works were highly sought after by the nobility and wealthy merchant class of the time.
As the name spread across Japan, it became associated with various place names, such as Kumasaka Village in Hiroshima Prefecture and Kumasaka Town in Kagoshima Prefecture. These locations may have served as the original homesteads for different branches of the Kumasaka family.
During the Edo period (1603-1868), the Kumasaka name appeared in various historical records, including the writings of renowned scholars and poets. Kumasaka Tōyō (1734-1805) was a celebrated haiku poet who contributed to the development of the literary form during this era.
In more recent centuries, the Kumasaka surname has been carried by notable figures in various fields. Kumasaka Hiromichi (1874-1949) was a prominent educator and principal of Tokyo Imperial University (now the University of Tokyo), known for his efforts in modernizing Japan's education system.
Another notable individual was Kumasaka Atsuko (1905-1995), a pioneering female journalist and writer who documented the experiences of women during World War II and the post-war reconstruction period in Japan.
While the Kumasaka name has its roots in Japan, it has also been adopted by individuals in other parts of the world, particularly among Japanese diaspora communities, reflecting the cultural diversity and migration patterns of the modern era.
Demographics
Ancestry and ethnicity for Kumasaka
Among Census respondents with the surname Kumasaka, the largest self-reported group is Asian/Pacific Islander at 66.4%. The next largest groups are Two or More Races (20.6%) and White (9.3%).
The bar chart below shows how Kumasaka 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 Kumasaka surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander66.4% · 71
- Two or more races20.6% · 22
- White9.3% · 10
- Hispanic or Latino3.7% · 4
Timeline
Historical Census data for Kumasaka
Kumasaka 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
#132,206
National surname rank
Recorded bearers 128
+12 bearers (+10.3%)
Per 100,000 0.04
Rank movement Up 1,831 places
2020
#151,639
National surname rank
Recorded bearers 107
-21 bearers (-16.4%)
Per 100,000 0.04
Rank movement Down 19,433 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #134,037 | 116 | 0.04 | First available Census row | First available Census row |
| 2010 | #132,206 | 128 | 0.04 | +12 bearers (+10.3%) | Up 1,831 places |
| 2020 | #151,639 | 107 | 0.04 | -21 bearers (-16.4%) | Down 19,433 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 Kumasaka 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 | #132,206 | #151,639 | -14.7% |
| Count | 128 | 107 | -16.4% |
| Per 100K | 0.04 | 0.04 | -10.5% |
Between the 2010 and 2020 Census, the number of Kumasaka bearers went from 128 to 107 (-16.4% change). The surname moved down 19,433 positions in the national ranking, going from #132,206 to #151,639.
FAQ
Kumasaka surname: questions and answers
How many people in the U.S. have the surname Kumasaka?
Name Census estimates that about 123 living Americans carry the surname Kumasaka. Using the current population baseline, that works out to roughly 1 in 2,786,621 residents.
How common is Kumasaka?
Kumasaka ranks #151,639 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 107 people with the surname Kumasaka. That is different from the site's living-bearer estimate (123), 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 Kumasaka.
Has Kumasaka become more or less common over time?
Between 2010 and 2020, the surname Kumasaka went from 128 recorded bearers to 107. That is a decrease of 21 (-16.4%). In the national ranking it fell from #132,206 to #151,639.
What does the Census say about the background of Kumasaka?
Among Census respondents with the surname Kumasaka, the largest self-reported group is Asian/Pacific Islander at 66.4%. The next largest groups are Two or More Races (20.6%) and White (9.3%). 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 Kumasaka in the 2020 Census, accounting for 66.4% (71 people in the source table).
What is the full ancestry breakdown?
Kumasaka appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (66.4%), Two or More Races (20.6%), White (9.3%). 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 Kumasaka (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 Kumasaka mean?
An uncommon Japanese surname possibly meaning "bear's slope" or "bear's hill." 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 Kumasaka (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 people have the surname Kumasaka?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.