People in Tokyo are flocking to a special kind of beauty pageant. Enthusiasts compete to find out who has the most beautiful koi, or brocaded carp. The colorful fish have been popular in Japan for decades and can sell for hundreds of thousands of dollars.

It's a wet and wild kind of beauty pageant in Japan. A contest to find the best looking koi fish.And competition can be quite stiff. Yasuyuki Tanaka farms these beauties called nishikigoi -- a kind of koi fish -- which are a result of careful cross-breeding. He brings his fish to contests and takes care of his precious aquatic jewels.

YASUYUKI TANAKA NISHIKIGOI FARMER "The quality of water means everything for nishikigoi fish, so our job is to create the best quality water for them. That is a very delicate task."

At this pageant in Tokyo, the stakes are high. Judges will vote for the champion fish, which can later net hundreds of thousands of dollars.

ISAMU HATTORI COMPETITION ORGANIZER "For these fish to win the championship, the curvature accounts for 60 percent, the contrast of colours 20 percent and the pattern 10 percent. The remaining 10 percent goes to its 'hinkaku' which means 'aura'."

There are many secrets of the trade when it comes to raising champion koi. And some may sound a bit simple but they're probably not.

MIKINORI KURIHARA KOI BREEDER "Put it this way, it's like looking after your own children every day. You care for your kids and want them to grow healthy. In the same way, you take care of these fish, appreciate them and adore them."

Nishikigoi farming is widely believed to have started about 200 years ago in the mountainous region of northwestern Japan. Today, koi fish is big business, making waves across the world. In 2016, Japan's koi exports reeled in 30 million dollars. That's a 50 percent increase over the past decade. But for Tanaka and other enthusiasts, they say raising beautiful koi is an art form and isn't just about the money.