One of the principal reasons people get tattoos are in order for them to symbolize something significant in their lives through art on their bodies. It is quite literally like wearing one's heart on one's sleeve or back or wherever it is one happens to have a tattoo placed. That is why tattoos of koi fish are so popular. It is because these fish are laden with symbolism in the Japanese and Chinese cultures from whence they come.
The meanings associated with koi are generally those of perseverance, aspiration, advancement, non-conformism or downright good luck. Perhaps this is because there is an ancient Chinese koi myth about these fish being the only one of their kind to swim up the waterfall towards the "Ryumon" or dragon gate at the upper edges of China's "Huang He" (Yellow River). It is at the dragon gate that it is said, the carp were transformed into dragons. From hence also comes the Japanese idiom, "koi-no-taki-nobori" or "carp swimming up the rapids," which is used to describe success in life perhaps in the same way that we use, "going against the grain."
Tattoos of koi fish are also taken to mean "love." This may be due to an old Japanese chronicle called the "Nihonshoki" which tells of how the Emperor Keiko fell in love with Princess Otohime (meaning Shy and Modest princess) and tried to make her visit him at Kukurinomiya Palace. The Emperor was known for taking pleasure in viewing his koi pond at the palace for this was common practice among the aristocracy of the Heian period (794-1185 BC). To the emperor's delight, the princess who happened to share his same pastime, could not help but finally pay him a visit. This paved the way for romance, all thanks to the koi fish.
Another symbolism for tattoos koi fish is that of masculinity, bravery and heroism. In Japan, koi are called "bushyi-go" or "Japanese warrior fish" because of their serene and determined manner of swimming, occasionally even jumping out of water. It is also said, that much like a samurai, koi fish do not flinch under the knife.
Tattoos of koi fish are often accompanied by backdrops of streams. To some, a koi swimming upstream or in rough water might mean one is struggling with a challenge. If the fish is swimming downstream it may mean that one has failed that challenge. Oftentimes however, koi representations are those of victory. Which is why even celebrities such as Cherliize Theron and her mother both sport the same tattoos of koi fish after their successful battle with cancer. Others like the late Alexander McQueen had a koi tattoo on his chest; popular singer John Mayer also wears one on his right shoulder.
Finally, a depiction of five golden koi may mean increased wealth or good luck, five being considered a lucky number in the East. This would be reason enough for anyone to have these beautiful carp close by. By having tattoos of koi fish one can be certain this is always the case.