Mutton Day (Yōniku no Hi)

What Is Mutton Day?

Every year on April 29th is "Mutton Day" (Yōniku no Hi). The date comes from a wordplay on numbers: "4" (yo/yō), "2" (ni), and "9" (ku) combine to spell "yōniku," meaning "mutton" or "lamb." The day was established by the Hokkaido Council for the Promotion of Jingisukan (Japanese-style grilled lamb) Culture. On the first day of Golden Week, a season for spring outings, the day encourages people to gather with family and friends around jingisukan and rediscover the deliciousness and nutritional value of lamb and mutton -- a healthy meat loved worldwide that has also evolved uniquely within Japanese food culture.

The History of Jingisukan in Japan

The deep roots of lamb and mutton's popularity in Japan are tied to national policy and pioneer history.

• Starting with wool sheep: From the Meiji to Taisho eras, "sheep farms" were established across Japan to produce wool domestically for military uniforms. The quest to find a delicious way to eat the sheep after their wool was harvested became the historical root of jingisukan culture.
• Becoming Hokkaido's soul food: After the war, marinades and special grilling pans were developed to remove the gamey smell of lamb, and the dish spread rapidly, centered on Hokkaido. Today, jingisukan is registered as a Hokkaido Heritage item and holds a firm place as a "communication dish" that strengthens community bonds.

Scientific Facts About "Carnitine" and Body Fat

Lamb and mutton have drawn scientific attention as "meat for beauty and health" among health-conscious people.

• L-carnitine content: Lamb and mutton contain dramatically more L-carnitine than other meats. L-carnitine plays a scientific role in transporting fatty acids into mitochondria to be converted into energy, and is expected to promote fat burning.
• Unsaturated fats and high protein: Lamb fat is rich in unsaturated fatty acids, said to help lower cholesterol. It's also a high-quality protein source containing a good balance of essential amino acids, supporting healthy body composition while maintaining muscle.

Interesting Facts About Lamb and Mutton

• The difference between "lamb" and "mutton": Meat from sheep under one year old is called "lamb," while meat from older sheep is called "mutton." Lamb has a milder taste and is tender, while mutton has a deeper, richer flavor and concentrated nutrition.
• One of the world's most beloved meats: In the Middle East, Europe, and Oceania, lamb and mutton face few religious restrictions and are among the most popular meats. France's "agneau de lait" (milk-fed lamb) is considered a top delicacy.
• The origin of the kanji for "sheep": The character is a pictograph of a sheep's head with horns. Many kanji with positive meanings -- such as "beauty" (美), "righteousness" (義), and "good fortune" (祥) -- contain the "sheep" radical, reflecting the animal's ancient association with abundance.
• The mystery of melting point: Sheep fat has a melting point of around 44°C, higher than the human body temperature, meaning it's harder for the body to absorb when cold. The key to enjoying it is eating it while it's hot.
• Rich in iron and vitamins: Lamb and mutton contain about twice the iron of beef, helping prevent anemia. They're also rich in vitamin B12, which supports metabolism -- ideal for recovering from spring fatigue.

Tips for Enjoying Mutton Day

• On April 29th, enjoy jingisukan or lamb chops for lunch or dinner. The distinctive aroma can stimulate the brain, evoking a sense of travel and adventure as you kick off Golden Week with energy
• Use this as a chance to switch to healthier eating. After taking in fat-burning L-carnitine, go for a longer walk or some light exercise to reset from the buildup of the new fiscal year
• Like sheep, value your "flock." Gather around a hot pot with family or friends and chat -- the protein in lamb is a building block for serotonin (the "happiness hormone"), nourishing both relationships and mood
• Try cooking with herbs and spices like rosemary or cumin, which pair well with lamb and also have antioxidant properties -- a great way to refresh your cooking repertoire

A Fragrant, Energizing Start to the Holiday

April 29th is a day to draw powerful energy from "lamb and mutton," a gift of nature. Just as sheep walk steadily within their flock, take a break from the busyness of the new fiscal year and share rich time with the people who matter most to you. With high-quality protein and fat-burning power on your side, both body and mind will feel lighter, ready for tomorrow's adventures. Gather around a sizzling plate of jingisukan and recharge for a refreshed version of yourself -- one bite at a time, filling your days with health and happiness.