同姓

1. Origins, structure, and basic meaning

• Structure: 同姓 (どうせい) is a nominal expression indicating that two or more people share a surname.
• Basic usage: 同姓の学生 modifies two students who share a surname, while 同姓なので gives the reason their given-name readings were also recorded.

2. Common pitfalls and similar expressions

• Surname and given name
  • 同姓 says only that the surname is shared, not the full name. The list therefore adds 名前の読み to distinguish the two students.