The room in which the little ogre appears is a reference to the red room in "Twin Peaks" (1990).
Maka's name is an anagram for the word kama which means scyth in Japanese.
Soul eater cannonically takes place in America. Specifically Death Valley, Arizona.
Death The Kids name is in reference to the gunfighter "Billy The Kid", and the use of two guns is in reference to where Billy was believed to hide out, Two Guns, Arizona.
There are 3 different repeat openings in soul eater