Peel, core, and roughly chop the Asian pears.

Combine the chopped pears, shochu (or sake), and lemon juice in a blender.

Puree the mixture until smooth.

Strain the puree through a fine-mesh sieve or cheesecloth-lined sieve to remove solids.

Press on the solids to extract as much juice as possible.

Fill four glasses with large ice cubes.

Place a green shiso leaf in each glass.

Use a blunt object to lightly muddle the ice and shiso to release their flavors.

Divide the pear mixture evenly among the four glasses.

Serve immediately.