Despite its name sansho pepper is not actually a pepper. I guess you might call it a spice with some peculiar traits. It’s earthy and tangy with a bit of lemon. When put directly on your tongue, you’ll notice a sort of tingling sensation.
Sansho pepper is usually sold ground, but you can also buy the berries and grind it yourself. It’s typically used on grilled foods like yakitori (chicken) or eel.
The sansho or prickly ash tree also yields the fragrant kinome leaves - which are often used as a garnish.