Because the Asagi resembles the Magoi, some beginners do not feel it is a Nishikigoi. There are three types of Magoi--"Tetsu (Iron) Magoi", "Doro (Mud) Magoi," and "Asagi Magoi." The last one is said to be the ancestor of the present Asagi. Asagi Magoi have a blue back with a light blue or white reticular pattern crossing it. Some scales have a blurred appearance. Hi appears on both cheeks, sides, and pectoral fins. There are two basic types, the Konjo Asagi and the Narumi Asagi. The black colour of the former is dark blue, similar to that of the Magoi. Narumi Asagi have scales with a dark blue center, shading into light blue towards the edges. Konjo Asagi as well as Tetsu Magoi are used to produce blackish Nishikigoi such as the Aka Matsuba, the Ki Matsuba, and the Ki-goi. Narumi Asagi on the other hand, are used to produce whitish Nishikigoi such as Kohaku, the Taisho Sanshoku, the Shiro Bekko, the Goshiki, the Ai Goromo, the Budo Sanshoku, and the Shusui.

Types include the Konjo and Narumi, plus the Asagi Sanshoku, also there are the Akedi or Mizu, and the Taki Asagi. As for the pattern, a spotless white or light blue head is desirable. Spots on the head quickly downgrade the koi's quality. Each blue scale on the back should be clearly seen. The contrasting white or light blue reticular pattern should be sharp and distinct. It is also a fundamental requirement that Hi appears on the cheeks, abdominal region, and fin joints. The colour of the Hi should be bright red. Red pectoral fins are called "Shusuibire"." Blue and red should be clearly divided. Brownish Hi degrades the koi. When the koi get older, their Hi tends to spread above the lateral line, which is usually undesirable. Black spots along the border of the Hi are disliked. The abdomen should be milky white. The "Akebi Asagi," sometimes called "Mizu Asagi," are light blue koi. "Taki Asagi," have a white band between the blue back and the red abdomen, "Asagi Sanshoku" have the characteristic Asagi blue back, but also have Hi markings on the head and sides and a milky white abdomen.