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Koi Varieties - Yamabuki Ogon

In the final ‘Koi Varieties’ blog in our Ogon group, we are looking at the Yamabuki Ogon. Like all the other Ogon koi, the Yamabuki Ogon is a single-coloured and metallic koi but this variety is the yellow-coloured version and was in fact the very first metallic koi.

As mentioned in our Platinum Ogon blog post (which can be found here:, the Ogon varieties were originally bred by a Japanese koi hobbyist called Sawata Aoki. Over 95 years ago, Aoki dreamed of one day creating a very special and unique koi that would be new and exciting and completely different to any koi that was available at the time. After a few unsuccessful attempts at breeding something new, Aoki heard that a young boy had found a wild carp in a river with beautiful golden stripes. Aoki was quite poor at the time but just knew that he needed this fish. So, he walked many, many miles and travelled a long way to see this golden carp and when he saw it, Aoki knew that this fish was important, that it would help him to finally achieve his dream.

Yamabuki Ogon koi from breeder Hirasawa

The boy was unwilling to give up his very special find but eventually, Aoki was able to convince the boy to sell the fish to him. Aoki gave the boy almost all his life savings in exchange for the fish but he was happy, his dream was about to come true. Aoki began his long walk home with his new fish, his mind racing with all the ideas and plans he had for this stunning fish. He could hardly imagine what this one wild carp could begin.

Unfortunately, Aoki had little success initially and almost gave up on his dream. His dreams that the wild carp would quickly produce a special new koi variety were quickly falling apart. Fortunately, however, Aoki had plenty of patience and spent the next 25 years slowly selectively breeding his wild carp with koi crap. With each generation, he chose the brightest and shiniest offspring to keep and breed on with each new generation being a little bit shinier, a little bit brighter and a little bit more consistent than the previous.

It wasn’t until 1946 that Aoki finally decided he had created a new koi variety and his new metallic koi was shown at koi shows. He had one particular koi that was shinier and brighter than all his others and stunned all the koi lovers who saw it. It has beautiful yellow skin and a stunning golden shine that caught the light beautifully. This was the very first Yamabuki Ogon and also the very first metallic koi carp. In fact, every single metallic koi that is available to us today is a direct descendant of that first Yamabuki Ogon koi.

After his success with the Yamabuki Ogon, some people thought that Aoki, having finally achieved his dream, would settle down and enjoy his new metallic koi. Certainly not! He continued to develop the Yamabuki Ogon and bred the variety with lots of other koi varieties to further produce more Ogon koi varieties. Aoki also set up his own koi breeding farm, Aokiya, where he began expanding into other, non-metallic koi varieties. Aokiya is now one of the biggest koi farms in Japan and Aoki is considered to be the leading breeder for lots of koi varieties including Gosanke, Goshiki, Kujaku, Hariwake, Kikokuryu and more!

Yamabuki Ogon koi from breeder Izumiya

Pongoi (Best Quality) Yamabuki Ogon Koi

The Yamabuki Ogon is very similar to the other Ogon koi when it comes to judging them. Most Ogon koi have just two criteria to consider. This makes it easy to judge a koi and also makes it easier for breeders to produce good quality koi. However, since it is easier to breed good quality Yamabuki Ogon koi, and since there are lots of Pongoi koi available, judges have to be much stricter with examples of this variety and therefore a koi must be perfect to be a Pongoi Yamabuki Ogon.

For example, a small colour bleed or a misaligned scale may be ignored on a Goshiki or another variety with a larger amount of judging criteria. However, on the clean, unblemished canvas of the Yambuki Ogon, such an imperfection is much more obvious and difficult to ignore.

When it comes to judging the Yamabuki Ogon, as mentioned above, there are two criteria to consider. The first is the colour itself and how consistent the colour is across the body of the koi. The body should have the same shade along the whole of the koi including the head, fins and tail. As with the other Ogon varieties, it is often easy to see when there are inconsistencies and blemishes in the colour, and these should be minimised for the best quality Yamabuki Ogon. The most important consideration for this variation is that it must have a clean body and ideally also have a clean head, fins, and tail, but the body is most important. Now, with regards to the colour itself, the ideal shade is a beautiful bright yellow so that with the metallic skin, the colour is comparable to liquid gold. Unlike the other Ogon varieties, the best Yamabuki Ogon should have a different colour on the fins, specifically a nice, clean snowy white colouration. This is because many koi keepers agree that the accents of white emphasise the beautiful colour of the body.

Yamabuki Ogon koi from breeder NND (This koi is older than the other koi featured on this page and so it is a much darker colour)

When judging the colour of a Yamabuki Ogon, it is very important to consider the consistency of the colour over the actual colour itself. This is because, for koi of this variety, the colour typically gets darker as the koi gets older. So for a young, tosai koi (up to a year old), the fish should be a lighter, sunshine yellow so that as the koi ages, its colour doesn’t get too dark. A Yamabuki Ogon that is already the bright and vibrant yellow colour of an older Pongoi fish is very likely to look brown and muddy by the time is it a few years old.

The other criterion to consider is the metallic sheen on the body of the koi. As with the yellow base colour, the most important thing about the sheen is that the amount must be consistent over the whole body of the koi and the lustre should have the same quality all over. A koi with poor but consistent lustre is considered better than a koi with both good and bad areas of lustre. The sheen should be visible over all areas of the body with no areas clearly lacking the reflective sheen. For a beautiful metallic koi, the skin should be shiny like a mirror and, on the yellow base colour of the Yamabuki Ogon, be comparable to a shiny gold medal or a flawless piece of gold jewellery.

The Yamabuki Ogon is truly a special koi. It is stunning in any pond with its beautiful gold-like colouration and many koi keepers love the variety for its history and its importance in creating metallic koi. A fantastic koi for any koi collector.

To browse our current stock of Yamabuki Ogon koi, have a look on our website:

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