A rainbow in the rice paddy.
Apparently, it's not a reflection of a rainbow in the sky, but a prism effect caused by iron bacteria floating in the paddy.

Photo courtesy of @donchan1101

This single photo looks as if a rainbow has descended onto the surface of the rice paddy. Vivid gradations of red, blue, and purple spread across the water, creating a fantastical scene completely different from the usual rice paddies we're used to seeing.

The post has garnered over 20,000 'likes' and sparked a huge reaction, with comments like, "Never knew this existed," "Absolutely stunning!", "It's like something out of a fairy tale," and "There's still so much I don't know..."

The Rainbow's True Identity: A 'Thin-Film Interference' Phenomenon Created by 'Iron Bacteria'

The scene while capturing this phenomenon

The photographer behind this shot is Tomohiro Tsuboi, who moved to Biei, Hokkaido, and works in agriculture while publishing his photography and video works. The photo was taken on May 23, 2026, at around 6:00 AM. Mr. Tsuboi commented on the experience, saying, "I knew this phenomenon could occur, but I was thrilled to actually see it with my own eyes."

At first glance, it might look like a rainbow in the sky reflecting on the water, but that's not the case. The true cause of the rainbow colors is a phenomenon called thin-film interference, caused by 'iron bacteria' floating on the paddy's water surface. When light hits the thin film that forms in iron-rich water environments, the interference of light can make it appear iridescent. It's a mystical sight that only appears when the conditions are just right, making it a rare encounter.

Hokkaido is home to many magnificent landscapes and famous tourist spots, but as this photo shows, surprising beauty can also be hidden in ordinary rural scenery. Why not pay closer attention to your immediate surroundings and search for the unique, fleeting wonders of the land?