The white short-sleeved T-shirt looks great on him, but what is that pearl keyring on the pants?

The white t-shirt on top is also so pretty.

The pants are also nice because the colors are unique.

What could that pearl keyring-like thing next to it that connects to the pocket be!

It stands out and helps with the design coordination, but

It reminds me of girls' play toys, so my eyes keep going to it.