First off, I love a menu typo. Not because I'm snarky, but because it sometimes shows the joint is chef owned, focusing on the food and not the flair. Anyhow, a warm and friendly Japanse + Korean sushi chef named Geno gave me a lesson on the shiso leaf. It's a member of the mint family, and pretty as all get out. The flavor is strong- floral, citrus, and very bright. He used it on sashimi plates, and in certain rolls as well.
I did a little research and found that Coke and Pepsi both make Shiso soda for the Japanese market. Interesting! I suppose it's related to the lemon basil fizzies you might find in a local speakeasy. Like shiso, basil is also a member of the mint family.