Actor Allusion: Jakoh's voice actor in the anime is provided by Shigeru Chiba, who in addition to being the show's narrator, also voiced the Filler Villain Joker. Given who he was modeled after, the casting of Chiba as Jakoh was obviously deliberate.
Cash Cow Franchise: Thirty years after the first chapter was published, Hokuto No Ken is STILL churning out new (spin-off) manga, merchandise and video games by the year....
Cross-Dressing Voices: In the TV series, Bat was voiced by a female voice actress, until he became an adult and was replaced by a male actor. Averted in the English dubs for the movie and TV series.
Fan Nickname: While technically "Sunagumo" (Sand Spider) was a derisive nickname Falco gave him, many fans refer to the Nameless Shura as such to differentiate him from the other nameless Shura warriors in the series.
The Jesus Beam, for Toki's ''Hokuto Ujouhaganken ("Merciful Face Break Fist").
There are two characters named Tobi. The first is Yuria's pet dog in the OVA Yuria Den, while the second is Bista's elder brother in Shin Hokuto no Ken/New Fist of the North Star. It's also the nom de guerre of one Obito Uchiha.
Kaioh is the last villain of Fist of the North Star 2, is the strongest of the Rasho and is a seriously evil git and master of the art of Hokuto Ryuken. The other Kaioh is more commonly known as King Kai. (Though his JP name is spelt "Kaio" and he's otherwise known as "Kaio-sama.")
In the English Dub of the movie, Shin and Yuria are coincidentally voiced by real life Happily Married couple Michael McConnohie and Melodee M. Speevack respectively. In the English dub of the TV series Kenshiro and Lin are the ones voiced by Happily Married couple Lex Lang and Sandy Fox.