What is "kokubo"

Kokubo (written: 國母 or 小久保) is a Japanese surname. Notable people with the surname include:

• Christina Kokubo (1950–2007), American actress
• Hiroki Kokubo (born 1971), Japanese baseball player
• Jun Kokubo (born 1980), Japanese footballer
• Kazuhiro Kokubo (born 1988), Japanese snowboarder