姓せいが変かわる

expression, godan verb (-ru)

to assume a new surname; to change one's family name

Used when someone takes a different surname, typically through marriage, adoption, or legal name change.

• 結けっ婚こんして姓せいが変かわった。

  My surname changed when I got married.

• 養よう子しに入はいると姓せいが変かわることもある。

  When you are adopted, your surname may change.