While this hand shape resembles a phone receiver, its roots are in the "Shaka" sign of surf culture. Therefore, it's often used not just to convey information like "call me," but also as a positive exclamation like "awesome!" or "the best!"

There's a story that the Shaka sign originated from a Hawaiian laborer who lost his three middle fingers in an accident and would wave his hand. The gesture embodies the "hang loose" spirit, meaning to live worry-free and relaxed, and is loved as a cool symbol by surfers and young people worldwide.