In a reference to the Robin Williams movie Jumanji.
Chu is referenced as to the word you as in the urban slang using the ch- to replace the you (u) sound in sentences (Chu-crazy; Chu alright?) Referenced as choo on urban dictionary (replaced the -oo with the -u for the purpose of the movie reference; therefore Chu-Manji is an urban slang version of jumanji the game from the movie.
This term shows particular reference to the jungle scene in the movie where the animals stampede out of the house.
You rolled the dice last night, and went Chumanji
Chumanji! (in reference to the movie's classic line)