A barrier option that aims to prevent a knock out. Pricing of such an option depends on the amount of time that the continuous time process remains in some designated intervals. This option presents an extension on the standard barrier option and also the Parisian option, where it is designed to lessen the need to intentionally shorting the underlying asset when the option is in-the-money and near to expiration from the perspective of the option seller on a vanilla barrier option.

The Tokyo option is also dubbed “edokko option“.