Koi fish is a kind of the nurturance management type of card game. The first generation of NFT card has the token anchor value. The first generation of NFT card has token anchor value, that is, the value of each KOI fish is to realize the function of intelligent contract automatic price feeding through the mysterious box games. The second generation of cards realize the cultivation function of Koi fish. Through breeding and feeding of male and female fish in pair, a variety of colorful and unique gene Koi Fish cards will be generated. They bring their own mortgage mining function of the Koi NFT. All the Koi Fish are obtained by opening the mystery boxes and cultivating. They also come with a certain amount of the physical strength, the attack, and the other game attributes. They have enhanced the application attribute of Koi. In the future, they can be reflected to the corresponding NFT card game. The Koi fish users can make use of its own different attributes of Koi NFT to participate in the game and plunders the different game props for trading and auction to obtain additional income.