Mamamoo MoonByul, Krystal's fan?

The pic of girl group Mamamoo's member MoonByul's appearance at a signing event
was published online gathering attention from the people.

Netizens who saw the pic reacted "didn't know that MoonByul was Krystal's fan",
"MoonByul was so happy to have a fan with Krystal picture on it!" etc.

▲Image Source: Online Community