Couple costume

Couple costume is the practice for a couple to wear the same hat, T-shirt, or other clothing in public to signal their relationship. It is especially common in South Korea and Taiwan, and is becoming more common in mainland China during its reform and opening.

Example
The style has been seen among the celebrity couple David Beckham and Charlize Theron.

In other languages

 * Korean language: 커플룩 (couple look), 커플 셔츠 (couple shirt)
 * Japanese language: カップルTシャツ (couple T-shirt)