Peppermint Day (Pepāminto no Hi)

What is Peppermint Day?

Every year on June 20th is "Peppermint Day" (Pepāminto no Hi). The date comes from a pun on the word "hakka" (peppermint/mint in Japanese), read as the 20th day of the month, combined with the idea that Hokkaido's refreshing early-summer climate in June matches the image of herbs. It was established in 1987 by the city of Kitami in Hokkaido (then the Kitami Tourism Association) to honor its history as one of Japan's leading mint-producing regions, and to encourage people to bring the refreshing, health-boosting qualities of mint into daily life.

The History of Kitami, the "City of Mint"

Hokkaido's Kitami once dominated the world market for mint.

• About 70% of the world market: In the early Showa era, the Kitami region accounted for roughly 70% of the world's mint production. Japanese mint under the "Kitami brand" supported global pharmaceutical and medical fields as a raw material for medicine and fragrance.
• Crystals of natural menthol: "Mint oil" extracted from mint plants, and the "menthol crystals" obtained by cooling it, were once valuable export resources. Before synthetic alternatives became common, this natural Japanese material was the global standard — a fact that speaks to Japan's manufacturing history.

The Science of How Menthol "Tricks" the Brain and Skin

The "coolness" you feel from mint has a biological mechanism behind it.

• Stimulating the TRPM8 receptor: Menthol, the main component of peppermint, directly stimulates a sensor in the skin and mucous membranes called TRPM8, which detects "coldness." Even if the actual temperature hasn't dropped, the brain receives a "cold" signal — producing a genuine sensation of refreshment.
• Boosting alertness and focus: Smelling mint has been shown to increase alpha waves in the brain and activate areas related to attention. This makes it a logical refresh technique for fighting off the afternoon slump that comes with seasonal fatigue.

Fascinating Facts About Peppermint

• Peppermint vs. spearmint: Peppermint is actually a hybrid of spearmint and water mint. Botanically, peppermint has a stronger, more intense menthol coolness, while spearmint has a sweeter, softer aroma.
• Mint after meals makes sense: Peppermint helps relax smooth muscle, including the muscles of the stomach and intestines. Drinking peppermint tea after a meal can aid digestion and ease stomach discomfort in a scientifically supported way.
• The science of insect repellent and antibacterial properties: Many plants release scents to protect themselves from insects. Mint's aromatic compounds have been confirmed to have an insect-repelling effect, as well as antibacterial properties against certain bacteria.
• The origin of the word "hakka": One theory traces the Japanese word "hakka" to the way mint plants become "thin/light" (haku) after extraction and refinement — a name rooted in logistics history.
• A scent even astronauts use: Certain mint scents have been studied for their ability to reduce discomfort and nausea in space. This highlights mint's role as a scientific tool for mental well-being in extreme conditions.

Tips for Spending Peppermint Day

• To mark June 20th (Peppermint Day), keep some mint essential oil or hakka oil near your desk. Use the scent during an afternoon focus dip to reset your brain's executive function.
• Try a "mint bath." Adding a few drops of hakka oil to your bathwater stimulates the TRPM8 receptor even after you've finished bathing, helping sweat evaporate more quickly — a great way to combat that sticky rainy-season feeling.
• Make your own "mint water" with fresh mint or mint tea bags, adding a refreshing twist to hydration. Mint's polyphenols also offer antioxidant benefits, supporting your health as early summer arrives.
• Look into the history of Kitami mint. Learning how Japan once supplied the world's mint demand is an intellectually rewarding way to appreciate Japanese craftsmanship and the wisdom of turning natural materials into industry.

A Refreshing Scent That Sends a Cool Breeze Through Your Mind, Clearing the Way to a Vivid and Energized Tomorrow

June 20th is a day to harness the "magic of scent" to transform the heavy air of early summer. The power of mint, which once brought comfort from Kitami to the world, still lives on as a reliable ingredient for making our lives more comfortable. Is your thinking feeling clouded by accumulated tasks and the early-summer heat? Today, try a drop of mint oil or a cup of mint tea. Its sharp coolness will sharpen your senses and create a refreshing "blank space" in your day. With a lighter mind, open the door to the new season with a breath of fresh air.