The Wind Kaleidoscope -- that's what people named the large geometric panels slowly moving in the breeze atop a building framed by vivid yellow metal.
Walking along the Okawa River, a major waterway that runs through Osaka city, pedestrians will easily spot the building because it stands out among its decidedly ordinary-looking neighbors.
Located in the central area of the major western Japanese city, the building was designed by Susumu Shingu, a 79-year-old Japanese artist internationally known for his mobile sculptures that makes use of wind, water and other natural elements.
Shingu's only architectural work houses the head office of corporate communication planning company Brain Center Inc.
Since being completed in 1992, the six-story building with its eye-catching appearance has attracted a steady stream of visitors from the fields of art and architecture, many of them from overseas.
"Sixty percent of visitors are foreigners. Many people come by word of mouth," Brain Center President Norio Inada says. "In the first few years, we had 300 to 400 groups a year from Europe and North America coming to view the building. Since then, we get around 100 groups."
The 67-year-old Inada says that when he planned to construct the company headquarters, he sought out Shingu to come up with something that symbolized the company's motto of "self reliance and independence."
Until then, Shingu had never designed a building, but he agreed to work on the project as he liked Inada's concept.
The structure, with its distinctive Wind Kaleidoscope sculptures, stands on a rather modest plot of land measuring 7 by 25 meters. One of its notable features is a spiral staircase that runs from floor to ceiling.
Five pieces of mobile sculpture are suspended in the middle of the staircase, moving gently in air currents generated by people going up and down the stairs.
There are three more sculptures atop the roof, turning freely in the wind. At the foot of the stairs is a concave mirror that reflects the moving sculptures with kaleidoscopic effect.
When it was completed, Italian architect Renzo Piano praised the building as a beautiful case of integrating art and practicality.
Brain Center's Inada says the sculptures "let us 'see' invisible winds, let us feel the winds with our heart." People inside can "get relaxed with the rhythm of nature," he added.
The building received Osaka city's "amenity award" in 1994 and was designated as a "picturesque building" by local artists in 2013.
Inada said that visitors to the Wind Kaleidoscope are welcome inside the building on condition they do not touch the sculptures or take photos.