A finger heart is a gesture in which a person performs a heart shape using their index finger and thumb.
In South Korea, it is a known symbol among K-pop stars and their fans. This gesture has become popular across Asia due to the popularity of K-pop and Korean dramas, and increasingly so in other parts of the world as a factor of the Korean Wave. Be proud, wear this shirt, spread love always. Saranghae (사랑해)!