Shinpachi is listening to Otsuu's newest single along with other members of her fan club, when they suddenly read in the newspaper about her having a boyfriend. Back in the Yorozuya, Shinpachi has entered a depression state, but suddenly Otsuu comes to request the gang's services. She is threatened by one of her fans to break up with her boyfriend, who is the lead singer of a band, Goemon, or he will kill her. The Yorozuya gang agrees to help her find the blackmailer and protect her from any possible attacks. For the next days, they are sticking close to Otsuu, while also searching for any possible suspects. Added to the suspects from Shinpachi's research, Gintoki adds the "mysterious shadow", a reference to Detective Conan anime. As the events fly, they eventually reach the channel, where Otsuu is participating in a show. At that time, we learn of how Shinpachi met and became a fan of Otsuu before she became a pop idol, singing in the streets. When he is in the bathroom, he overhears one of Goemon's calls, who has been taking advantage of Otsuu and hasn't any real feelings for her. Infuriated, he beats him up and joind Kagura and Gintoki, who have been putting their own show trying to find the culprit. It appears though that none of their suspects was guilty. The mysterious shadow appears in Otsuu's room and after a wild chase throughout the channel, he is caught and proved to be an Amanto that just wanted Otsuu's autograph. Shinpachi finally reveals the real culprit, who was Otsuu's mother and manager. She has done this, because she wanted to warn Otsuu of the dangers that exist in the show business and that every man is not good for her. The episode ends with Shinpachi and the rest of the fan club still supporting Otsuu, even if the scandal harmed her reputation a bit.
踊る大捜査線 Odoru Daisousa sen's 2 main leads, 室井慎次 Muroi Shinji on the left (played by 柳葉敏郎 Yanagiba Toshirou), 織田裕二 Oda Yuuji on the right (played by 青島俊作 Aoshima Shunsaku)
The first to be parodied when Gintoki and Kagura are about to step out of Yorozuya after talking to Otsuu is 踊る大捜査線 （おどるだいそうさせん）odoru daisousasen, known as Bayside Shakedown in English. The way the anime characters' names are labelled on screen mimick those of the series.
Gintoki takes on the persona of 織田裕二 Oda Yuuji, a low-ranking police sergeant in the Wangan Precinct played by haiyuu 青島俊作 Aoshima Shunsaku, which is the actor on the right. However, he takes on the name of Ishihara, which is likely to be the name of the series producer which is 石原隆 Ishihara Takashi. The Gintoki cameo bears no resemblance to this producer.
Kagura takes on the persona of 'The Suspect Giba-chan', the physically shorter high-ranking Senior Superintendent 室井慎次 Muroi Shinji of the Hiroshima Prefecture Police HQ. This character is played by haiyuu 柳葉敏郎 Yanagiba Toshirou, thus explaining the Giba-chan moniker. 'The Suspect Muroi Shinji' 「容疑者 室井慎次」 is actually the title of 1 of the episodes, as well as movie title released in 2005.
Gintoki concluded after this that Shinpachi must be the 交渉人 koushou nin aka negotiator. Another episode cum movie title is 「交渉人 真下正義」 koushou nin Mashita Masayoshi, played by haiyuu ユースケ・サンタマリア Yu-suke Santamaria, which explains why Shinpachi burst out saying he is not Santamaria.
Gintoki's nose and ears, and the green overcoat is intended to spoof 青島俊作 Aoshima Shunsaku's role, while Kagura's eyebrows and suit are intended to spoof 柳葉敏郎 Yanagiba Toshirou.
The mystery shadow 謎の影 nazo no kage is from 「名探偵コナン」 Detective Conan, the moustached man who appeared out of no where is 毛利小五郎 Mouri Kogorou aka 眠りの小五郎 nemuri no mouri kogorou, while Gintoki hiding behind the couch with the red bow-tie is mimicking 江戸川コナン Edogawa Konan aka Detective Conan. For more details, refer to Wikipedia Link.
At the scene where they supposedly discovered Mu-san's body, the background music came from 「古畑任三郎」Furuhata Ninzaburou starring 田村正和 Tamura Masakazu as a Police Lieutenant. Gintoki introduced himself as Ginzaburou.
When Otsuu's mother was confessing to the Yorozuya trio, a few different cameos appeared -
First, Gintoki adopted the persona of Arthur Conan Doyle's Sherlock Holmes, while Kagura took on Agatha Christies' Hercule Poirot.
This is followed by Gintoki as 金田一 耕助 Kindaichi Kousuke and Kagura as his grandson 金田一一 Kindaichi Hajime of 「金田一少年の事件簿」kindaichi shounen no jikenbo manga. The grandfather is a famous (fictitious) detective in 横溝正史 Yokomizo Seishi's mystery novels.
Third cameo - 又市の錫杖を持った京極堂 （銀時）、鈴を持った又市（神楽） Summer of the Ubume(?)
キャビンアテンダント刑事 'The Cabin Attendant Files' is written on the movie clap board shown when Otsuu is doing 1 of the takes - this is a spoof of 「スチュワーデス刑事」 'The Stewardess Files', from Fuji TV, about 3 stewardess on JAL flights, classified as a 'travel-gourmet-mystery'.
When Otsuu said thank you to Shinpachi at the end of the episode, she called him 'Shinichi'. This is the real name of Detective Conan, which is 工藤新一 Kudou Shinichi.
List of suspects -
Tamo-san is referring to real-life comedian タモリ Tamori-san. One of his more famous show is 笑っていいとも! waratte iitomo! aka 'It's OK to laugh', which was spoofed as utatte iitomo! aka 'It's OK to sing' when Shinpachi and his fan club members first appeared in this episode reading the news of Otsuu's relationship. For more details, refer to Japanese Wikipedia Link.
Mu-san, the producer is referring to 武藤大司 Mutou Daishi, from TV Tokyo, in charge until Episode 112.verify: from Dentsu
funagoei 船声英司朗 (actor)?
賀木苦毛子 (actress) gakiku keko?
Kagura sporting 2 pony-tails in a red jump-suit and saying the phrase 'お前のやったことは、全てまるっとお見通しだ' omae no yatta koto wa, subete marutto o mitooshi da -
The female protagonist 山口久美子 Yamaguchi Kumiki of 「ごくせん」 gokusen is the character Kagura is spoofing with 2 pony-tails and red jump-suit. The series revolve around the adventures of a Maths teacher dealing with difficult students in school. The side parting of the hair-do on Kagura indicates that it is probably a reference to the TV drama version's live actress 仲間由紀恵 Nakama Yukie, rather than the manga version.
However, the line she spoke belongs to 「トリック」 Trick, a comedy/drama that starred the same actress but playing the role of 山田奈緒子 Yamada Naoko, a penniless magician forced to team up with a physics professor to solve mysteries to earn a living. That was why Gintoki said to Kagura that her cameo does not resemble the magician role at all, although it was almost identical to the Maths teacher role.
When the suspects were lined up in a row, Tamo-san was asked why he was present, to which he replied, he is the ストーリーテラー 'story-teller' -
this is a drama series which aired during the golden time of 1900~2200 hours, presenting a series of mystery short clips of about 25 minutes in which Tamori-san is the narrator. He also acted in some episodes. (to verify again?)
Otsuu's hp ringtone ?
Kagura mentioned the plot for the final episode, concerning the combined efforts of ピン子Pinko (acting as 小島五月 Kojima Satsuki) and 春恵 Harue (haiyuu 赤木春恵 Akagi Harue, acting as Pinko's mother-in-law 小島キミ Kojima Kimi) - this is referring to the series 「渡る世間は鬼ばかり 」 wataru seken wa oni ba kari, in which daughter-in-law and mother-in-law tried their best to keep the family ramen shop going, against the daughters and sons-in-law who wish to sell it off.
Kagura ran to Gintoki announcing ピン子 Pinko, who is acting in the series 「渡る世間は鬼しかいねえコノヤロー！！」 aka 'This world is filled with ghosts, you ba$tard !!' has arrived -
possibly referring to Gintama's earlier Episode 5 in which Hijikata and Okita rushed back to Shinsengumi HQ to watch (since they forgot to set the recorder to tape it)
「渡る世間は鬼ばかり 」 wataru seken wa oni ba kari aka 'Traversing in this world are merely ghosts', is a well-known heart-warming TBS family drama about a couple and their 5 daughters, starring 泉ピン子 Izumi Pinko as the second daughter.
this is a possible twist of the expression '渡る世間に鬼はない' wataru seken ni oni wa nai aka there are no devils in this world
The backdrop of the show that the shadow broke through while being pursued by Yorozuya is a reference to 開運! なんでも鑑定団 kai un! nan demo kantei dan, a TV Tokyo variety show where people bring all kinds of valuables for a specialist jury to judge.
The signboard that Gintoki's bokutou hit while chasing mystery shadow 謎の影 nazo no kage showed レディス4王 選手権 Ladies 4 King Championship. レディス4 Ladies 4 is a lifestyle programme, one which both Hijikata and Okita again like to watch as shown in Episode 9.
The TV station building is a possible reference to TV Tokyo's HQ, with similar circular motif on the station corporate logos.
Ketsuno Ana got married in this episode, Otsuu released a 3rd new single 「お前の兄ちゃん××（ひきこもり）」 Your brother is XX (hikikomori).
Goemon is listed as the leader of pop idol group 反侍 hansamu. The romaji in used here is identical to the romaji for the word 'handsome' in Japanese, but the literal meaning of the kanji is 'opposite of samurai'. Goemon uses gozaru on almost every sentence only when talking to Otsuu and not while on the phone in the toilet, displaying a false affectation.