The Scott Adkins Ninja movies have a curious connection to the 80's ninja movie craze, particularly the second film, 2013's Ninja II: Shadow of a Tear. Both of Adkins' Ninja movies were directed by filmmaker Isaac Florentine, well-known for his directorial work on such straight-to-video action classics as Undisputed 2: Last Man Standing and Undisputed 3: Redemption, with both Adkins and Florentine having a big hand in the very notion of straight-to-video action classics full-stop. Ninja marked Adkins' first time as a leading man, and he's since gone on to be one of the most revered martial artists in modern action movies, and his portrayals of American Ninjutsu master Casey Bowman harkens back to the American Ninja franchise of the 1980s.

Anchored primarily by Michael Dudikoff and later David Bradley, the American Ninja movies are dated and thoroughly goofy affairs by modern sensibilities, but for lovers of ninja movies, they're must-sees. The first Ninja carried over the comic-book-inspired tone and feel of the American Ninja films into the 21st century, complete with Casey taking on an underground cult single-handedly and his supervillain-style ninja suit and tech deployed by his enemy Masazuka, played by Tsuyoshi Ihara. However, the biggest and most direct connection that Adkins' Ninja films come in Shadow of a Tear in the form of Kane Kosugi.

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In the movie, Kosugi portrays Casey's fellow Ninjutsu master Nakabara, with Kosugi himself being the son of ninja movie icon Sho Kosugi. The 80s ninja boom saw Kosugi notably headline a trilogy of ninja film, consisting of Enter the Ninja, Revenge of the Ninja, and Ninja III: The Domination. Moreover, Kane himself also appeared in Revenge of the Ninja as Kane Osaki, the son of his father's character, Sho Osaki. The young Kane also appeared in other martial arts heavy 80s action films with his father, such as 9 Deaths of the Ninja and Pray for Death, as well.

Ninja 2 Shadow of a Tear Scott Adkins and Kane Kosugi fight scene pic

Though the first Ninja didn't quite rise to the heights it could have, it was still a fun, action-packed ride, and showed just far ahead of the theatrical game Adkins and Florentine already were. Its sequel, Shadow of a Tear, is arguably one of the best ninja movies ever made, if not the best, and Kane Kosugi absolutely helped make that so. Though the nature of Nakabara's role in the movie means he has fewer fight scenes than Casey, he's nevertheless a marvel to behold, with the final showdown between Adkins and Casey a true war of ninja masters. Kosugi also later appeared on Adkins' YouTube series The Art of Action, with the two breaking down the making of their final battle in the movie.

If Ninja 3 ever happens, the bar has clearly been set exceptionally high by Shadow of a Tear, with frankly the entire ninja sub-genre now having quite a tall order to live up to by its standards, with Netflix's Daredevil being its only real equal among contemporary ninja media. Ultimately, Scott Adkins' Ninja films were an exhilarating update of the ninja films of the 80s, even injecting a little of their nostalgic, superhero-esque feel into a more modern setting. Still, their biggest Easter Egg to their 80's ancestors was bringing Kane Kosugi back into the Ninjutsu action game for Ninja II: Shadow of a Tear.

NEXT: Undisputed: How Scott Adkins Saved The Franchise