Kingyo Used Books (金魚屋古書店 Kingyoya Koshoten?) is an ongoing manga series written and illustrated by Seimu Yoshizaki. It follows the happenings which revolve around a small used manga store, specializing in old and obscure manga. The series is loaded with several references to classic manga, such as Dr. Slump and Moretsu Ataro, as well as foreign comics like Jean Giraud's Blueberry. The series is serialized in Shogakukan monthly seinen Ikki magazine and as of May 2010 serial chapters are collected in ten tankōbon. The series is licensed in North America by Viz Media under the their Viz Signature Ikki label.
The plot is focused around a used manga store, and has a series of vignette-style chapters revolving around different characters, a la Pet Shop of Horrors. It extols the value of reading manga in one's life, and is notable for having references to several well-known, as well as obscure manga, from the smash-hit Dr. Slump, to the nary heard-of Billy Puck.
This series is written by Seimu Yoshizaki and is serialized in Shogakukan monthly seinen Ikki magazine. The serial chapters are collected into ten tankōbon, the first released on December 24, 2004, and the tenth on April 28, 2010.. This series has a two volumes prequel Kingyoya Koshoten Suitouchou (金魚屋古書店出納帳?) also serialized in Ikki, both volumes were released on December 24, 2004.
Carlo Santos in his Anime News Network column "Right Turn Only" gave the manga a grade of "B", saying that "if you want to get a non-manga fan into manga, this is probably not the manga to give them." The critic went on to say, "Kingyo is, if anything, too fixated on giving history lessons, trying to drown the reader in footnotes and details rather than letting the series speak for itself."