両陛下

1. Origins, structure, and basic meaning

• Structure: 両陛下 is read as りょうへいか; 両 means both and 陛下 is the honorific “Majesty,” together yielding “Their Majesties.”
• Basic usage: Use 両陛下が登場する when both are the subject and 両陛下の帰還 for their return.

2. Common pitfalls and similar expressions

• Not a general plural
  • 両 groups exactly two paired people, unlike a general plural expression that could include three or more.
• Honorific built into the term
  • 陛下 is already the high title “Majesty,” and 両陛下 forms the respectful expression “Their Majesties,” not an ordinary human plural.