<human>:  Could Casio's first invention be worn around the ankle?
<bot>: No, Casio's first invention was not something that could be worn around the ankle. Casio's first invention was the yubiwa pipe. The yubiwa pipe was a ring worn that held a cigarette in place worn on the finger. Ankles are several inches thicker than fingers. So Casio's first invention could not be worn.