Ashita no Joe, Rainbow: Nisha Rokubou no Shichinin Recommendations
Same historical background and similar characters.
Old Japan, prison, boxing, stubborn characters (!) and both are really sad
They both have similar settings,boxing,kids with really rough lives but manage to somehow get by and the roughness of early 1900's japan.
Timeline is centered around early 1900s of Japan. Both AnJ and Rainbow have very interesting, unshakable and self-willed characters. Both are drama with a dark plot. Both show its characters dealing with life's ups and downs. Both have an akin backdrop of prison and boxing. AnJ is centered more around boxing while Rainbow is centered more around the prison.