Shiso and perilla are both from the mint family, but they are different varieties. Shiso leaves are larger and have a more flavorful taste, while perilla leaves are smaller with a milder flavor. Both can be used for culinary purposes, but shiso is generally preferred as it has a stronger aroma and bitter taste. Perilla, on the other hand, is often used in Asian cuisine as a garnish. In Japan, shiso leaves are also used to make umeboshi (pickled plums). Shiso is also known for its medicinal properties and has been used in traditional Chinese medicine for centuries.