The playful images, taken with an iPhone mounted on a tripod, also portray the pleasure Mr. Bon and Mrs. Pon (otherwise known as Tsuyoshi and Tomi Seki) derive from each other's company, decades after the college sweethearts married.

They have their daughter to thank for their unlikely internet fame, Mrs. Pon told the Guardian from their home in the northeastern city of Sendai. "She took photos of us and posted them on her own Instagram account. She received lots of comments so suggested that we start our own account."

These two have always had similar tastes in clothes but now they are taking it to another level. "It's not just about coordinating our clothes," Mr. Bon explained. "We try to choose outfits that complement our surroundings."

Much of their wardrobe comes from Uniqlo and other high street chains but they believe it's the no-frills approach that has contributed to their popularity. "Of course we're happy to be described as style icons in the media, but that's not really how we see ourselves. We wear simple, inexpensive clothes that anyone can buy," Mrs. Pon said.

Outfits aside, Tsuyoshi and Tomi hope to convince other older couples that retirement should mark the start of a second life.