City Sushi/Trivia

Trivia

 * Janus is a Roman god generally depicted with two faces on the front and back of his head. Although he's considered the god of beginnings and endings, in this case it's also a reference to Dr. Janus having multiple "faces" (personalities).
 * When Butters is burning his other identities, he says "No more porn star Butters" this may mean he had underage sex, or just likes pretending to have sex.
 * Cartman, Stan, Kenny and Kyle have no speaking lines in this episode, they only appear once in the audience when Tuong Lu Kim and the Japanese man are talking about Asian diversity. As Kenny did not appear in the previous episode also, this marks the second episode in a row where Kenny doesn't do or say anything this season.
 * Inspector Butters is a reference to the episode "Butters' Very Own Episode", where Butters follows his father around for his mother as an 'Inspector'.
 * The word 'shit' is once again uncensored.
 * Butters mentions Professor Chaos, his dark alter ego from "Professor Chaos", and other past episodes. However how he mentions him suggests he now only sees Chaos as a play character rather than his desire for revenge.
 * City Wok is not the only Chinese restaurant in South Park. There is also a P.F. Chang's, however, it could've been destroyed in an episode where the town faces destruction, like "Pandemic 2: The Startling " or "201".
 * A running gag throughout the episode is the other characters unable to see a difference between Chinese and Japanese people, as they always refer City Sushi as a Chinese restaurant and from the "increased Chinese culture" they name the area Little Tokyo, which is Japanese.
 * Dr. Janus has at least seven split personalties not including himself; The Old Man, Billy, The Evil Psychotic One, The Con Artist, The Pizza Man, The One Who Sings, and Lu Kim.
 * Butters burns all his alter egos except Professor Chaos which means he might return.
 * It is the first episode to air in June since 2002 episode Simpsons Already Did It.
 * When Tuong mentions that Japan has the highest suicide rate, this statistic may be outdated, since in 1990s suicide rates in Japan decreased significantly.
 * In HUMANCENTiPAD, Junichi Takiyama states he cannot read English. However, in this episode, he reads a letter from Lu Kim. He may have taken it upon himself to learn since then, especially after the horrors that cursed him. On the other hand, the letter may have been in Japanese, his native language, "translated" for the audience's sake.

References to Popular Culture

 * When Butters films himself, it is a parody of Paranormal Activity, proven when Butters says, "This is like Paranormal."
 * The final scene where Tuong Lu Kim is sitting in prison and saying he "doesn't harm a fly" is an homage to the ending of Alfred Hitchcock's "Psycho".
 * When Dr. Janus is riding a tricycle, frightening Butters and calling himself Billy, This is a reference to the SAW movies.
 * In the scene where the Chinese and the Japanese men are talking about the Asian Diversity the song that plays is LMFAO's "Party Rock Anthem".
 * In the scene where Dr. Janus says he's been scamming the town for 7 years, his computer's logo says "Bell". This could be a reference to real life computer company Dell. This has also appeared in other episodes, like "T.M.I.".
 * Dr. Janus' personality-jumping meltdown, complete with removal of hairpiece, is likely a reference to the film "The Stepfather", where actor Terry O'Quinn played a man who swapped identities frequently (and eventually involuntarily), sometimes removing his hair piece to distinguish.
 * When Janus stated that MPD isn't real, is based on the dispute psychologist's have where most do not believe in an actual case of MPD has been offically proven.

Continuity

 * Butters previously underwent psychiatric evaluation in "The Death of Eric Cartman", when his parents thought he was hallucinating and seeing a ghost.
 * The Stotches immediately dismiss their son's "trouble making" as not because of their parenting, claiming "they're awesome". Once again playing on the fact they are completely oblivious to how cold and harsh they treat him.
 * Once again Butters is blamed entirely for something he has practically little involvement in, and is grounded.
 * Inspector Butters is from "Butters' Very Own Episode".
 * The Japanese man is from "HUMANCENTiPAD".
 * When Butters is running up the stairs of Dr. Janus' house, Dr. Janus says, "You can't run forever!" This line was said by Billy Thompson in "Insheeption" directed towards Mr. Mackey as a kid. One of Janus' personalities is called Billy, but the personality is a good guy.
 * Bradley Biggle can be seen in the crowd at assembly, implying that he has returned (his last appearance was in "Coon vs. Coon & Friends".
 * While burning away his stuff that makes him into whatever he believes to be, Butters was about to burn away his Professor Chaos costume until Dr. Janus intervened. It is unknown whether Butters will be Professor Chaos again or not in future episodes.

Goofs

 * In the press release from South Park Studios, part of the description (or synopsis) of the episode was given as, "the boys want to help Butters find out what's really happening to him but Butters may not like what they find". However, this could've been changed from the episode of South Park Studios kept it the same.
 * The medical term for Multiple Personality Disorder is actually Dissociative identity disorder, however Dr. Janus refers to it as MPD.
 * When Mr Mackey is addressing the school at the Asian Diversity assembly, many children can be seen twice or more in the crowd, as well as some alternate versions of characters. This includes Tommy Turner, Bill Allen, Sally Turner and some unnamed characters.