유

How it's spelled in English

• Yu(official)
• Yoo

Usual hanja

劉 — an ancient axe; the surname of China's Han emperors

Well-known clans (bongwan)

강릉 유씨

A bongwan is the ancestral home of a clan — two Kims from different bongwan are different families.

Population

• 유(劉) 302,511 people, 0.6% of the population
• 유(兪) 167,927 people, 0.3% of the population
• 유(柳) 478,990 people, 1.0% of the population

Statistics Korea, 2015 Population and Housing Census · The census counts each spelling + hanja as a separate row; they are shown as listed, not added up.

About it

유 is written with several characters — 劉, 兪 and, for many families, 柳 — so the same name can mean different clans.