Opening scene is a news broadcast which contains 3 gang members of the Shokkas. They are also the thugs in the forest. There is also guns and drugs on a table among which is CPH4. CPH4 is from the Luc Besson movie Lucy starring Scarlett Johansson.
News channel is Raccoon city which pays tribute to the Resident Evil franchise.
Characters from the movie include Sam from the name Samurai and scar because he has a scar. The master is based on a true character is Japanese history who fought with Master Musashi. Neko means cat which pays tribute to the director's daughter Caterina Haddon. Characters named Ichi, Nee and San were named because of the order they were killed in - one, two and three.
Inspiration for the movies were mainly based on the blind samurai movies from Japan.
Nee yells Hadouken before getting slashed. This is a reference to the video game Street Fighter.