Family name Mu-In (Mu-In 
) , globally, is an extremely rare last name. The family name Mu-In is habitual in South-eastern Asia, particularly Philippines, where it is an extremely rare surname. Also, Mu-In is the forename as well as the last name. Parts of the name also exists independently as a first name Mu, and a last name In.
| VARIANT | COUNTRY |
|---|---|
| Mu-In | Philippines |