We had the privilege of speaking with the family of Masao Kadoguchi, one of Japan’s longest-living men in Japan and the oldest living person in Nagasaki Prefecture. Through their words, we came to understand his life, shaped by love, care, gratitude, and a strong awareness of health. Here, we share his story.

Upbringing and Marriage

Masao Kadoguchi (門口正雄) was born in Kagawa Prefecture, Japan, on September 7, 1915. In his early twenties, while working at a hotel in Hong Kong, he met a Japanese colleague who later became his wife. Their first daughter and son were born in Hong Kong before the family returned to Japan prior to the end of World War II. They settled in his wife’s hometown of Nagasaki Prefecture and went on to raise six children.

A Devoted Family Man

According to his eldest daughter, Kadoguchi was a man who expressed his love not only through words but also through daily actions. At a time when it was uncommon for men in Japan, he lightened his wife’s burden of raising six children by actively helping with household chores such as scrubbing floors and cleaning. He ironed his own shirts and managed his personal matters independently, reflecting both his self-reliance and his deep respect for his wife.

When his children were young, he prepared a swing and a slide in the garden and often surprised them with thoughtful gifts after quietly asking what they wanted.

A Longstanding Fish-Based Diet

Kadoguchi maintained a consistent eating routine for many years. Until the age of 106, while still living at home, he ate grilled fish every morning and sashimi every evening. His wife, an excellent cook, supported this habit by visiting the morning market daily to buy fresh fish. Dinner typically included two servings of sashimi, two or three small side dishes, and a hearty miso soup with egg and a variety of vegetables, including mushrooms. After her passing, his eldest daughter continued this routine, recreating her mother’s flavors to support her father, Kadoguchi.

He also ate a small portion of grilled eel each night. While watching sumo or baseball on TV, he took his time with meals, often spending about two hours at the table, chewing carefully and eating slowly. Even at 110, he continues to eat three meals a day at a relaxed pace, following the principle of never eating beyond 80 percent full.

Health Sustained by Environment and Active Living

In addition to his diet, Kadoguchi benefited from the environment of Nagasaki, a city known for its steep slopes. He walked these hills regularly until around the age of 100 and was described as being very energetic.

Curious and enthusiastic, Kadoguchi pursued many interests. He dug a pond in his garden to raise goldfish and carp, built a greenhouse to cultivate chrysanthemums and orchids, and enjoyed watching sports, reading newspapers daily. He also had a humorous side, often making witty remarks while watching television that made his family laugh and lightened the household atmosphere.

Since Turning 106

After his wife passed away at age 97, Kadoguchi continued living at home with the support of his second daughter, sometimes cooking for himself. Since the age of 106, he has been living in a hospital in Nagasaki City.

There, too, he is known for his warm personality. He remembers the names and faces of the nurses and places importance on showing gratitude. When receiving care, he often puts his hands together and says “thank you,” a practice that reflects his appreciation for those around him.

His favorite phrase is “Ganbarimashō!” (“Let’s do our best!”), and even now, he says it with strength in his hospital room or during phone calls with his family, giving encouragement to those around him. He also expresses his gratitude cheerfully, often saying, “Thanks to my second daughter, I am able to keep living this long!”

Masao Kadoguchi (門口正雄) , during the mayor’s visit in September 2025 (Source: Asahi Shimbun).

Keys to His Longevity

As described throughout his life story, Kadoguchi’s longevity can be linked to several consistent habits: a lifelong fish-based diet, the practice of eating slowly and chewing thoroughly, and the principle of stopping at about 80 percent full. These routines supported his strength—he reportedly never caught even a cold until the age of 106. Combined with daily activity in Nagasaki’s steep environment and his steady habit of expressing gratitude, these practices continue to be part of his everyday life at 110.