A single photograph taken in the rural landscape of Hokkaido has become a hot topic on social media. It shows a rainbow-colored gradation spreading across a rice paddy. However, this mysterious phenomenon is not a reflection of a rainbow in the sky. So, what is its true identity?

This single photo looks as if a rainbow has descended upon the surface of a rice paddy. A vivid gradation of red, blue, purple, and other colors spreads across the water, creating a fantastical scene completely different from the familiar sight of a rice field.

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

The Rainbow's True Identity: An "Optical Interference Phenomenon" Created by "Iron Bacteria"

The photographer capturing the phenomenon.

The photographer is Tomohiro Tsuboi, who moved to Biei, Hokkaido, and works as a farmer while publishing his photography and video works. The photo was taken on May 23, 2026, around 6:00 AM. Mr. Tsuboi commented on the experience, saying, "I knew this phenomenon could happen, but I was so happy to see it with my own eyes."

At first glance, it might look like a rainbow in the sky reflecting on the water's surface, but that's not the case. The rainbow-like colors are actually due to a thin-film interference phenomenon caused by "iron bacteria" floating on the water of the rice paddy. When light hits the thin film that forms in water environments containing iron, it can appear iridescent due to light interference. 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 instance shows, surprising beauty can also be hidden in ordinary rural scenery. Why not pay closer attention to your everyday surroundings and search for the unique, fleeting masterpieces of the land?