Lego Ninja immediately followed the Fright Knights theme, which had been in production from 1997 to 1998.

In contrast to Fright Knights, Lego Ninja took its influence from a more realistic starting point and was set in mountainous Japan with medieval buildings.

[3] The toy sets featured a variety of buildings and vehicles, including fortresses and boats.

The robber's crest was a red, black and silver bull's head.

[5] A year later, in early 2011, Lego released the Lego Ninjago theme and associated television series Ninjago: Masters of Spinjitzu, which took heavy inspiration from the Ninja theme.