Mugen Shinshi

is a Japanese manga series written by Yosuke Takahashi. The first manga was serialized under Manga Shonen magazine from January 1981 to December 1982, with all 6 chapters compiled into 1 tankobon. A second manga chaptered was serialized from January 1982 to January 1991 totaling up to 68 chapters under several labels. An OVA based on the second manga was released on February 1987.

A third manga chaptered was serialized from July 1982 to April 1991. A fourth manga chaptered was serialized from July 1992 to May 1996. A fifth manga under three trilogy chapters titled was serialized in the "Mystery Magazine" from 2004 to 2007.

Plot
The mystery adventures of Mamiya Mugen, a young detective of the Japanese Showa period.

Adventure Drama OVA
When a strange group of men attempt to kidnap Atsuko Fukune, a club dancer, she seeks the help of Mamiya Mugen, a famous detective who also happens to be a child. When it turns out that other girls have gone missing, Mamiya, along with his butler Alucard, springs into action to solve the mystery.