Episode 35

Infiltrating the Entertainment District (遊郭潜入) is the 35th episode of the Kimetsu no Yaiba TV anime series, and the 9th episode of its second season.

Synopsis
After Tanjiro visits the Rengoku residence and meets Kyojuro's younger brother, Senjuro, to deliver Kyojuro's last message, Tanjiro spends his days training and completing missions. One day, he returns to the Butterfly Mansion to find Sound Hashira, Tengen Uzui, attempting to take Aoi and Naho away on a mission against their will. Tanjiro, Zenitsu and Inosuke offer to go on that mission instead, and they head to their next destination - the Entertainment District.

Plot
Tanjiro and Inosuke are not aware of what an entertainment district is, causing Zenitsu to be flustered at their naivety. The Sound Hashira Tengen Uzui quickly announces himself as a god and addresses the trio as trash, telling them to pound it into their heads as the first thing. Though Zenitsu is unable to believe what Tengen is saying, Tanjiro asks what he is the specific god of, to his friend's bewilderment. Tengen answers he is "the God of Flashiness" and "the God of Festivals". Inosuke joins and calls himself the "King of the Mountain", only to confuse Tengen and infuriate Zenitsu more so at their brash confidence. Tengen decides to lead the mission and runs on ahead, his speed amazing the three Demon Slayers.

The party arrive in to their destination; Tanjiro looks on in wonder of everything unfamiliar to him. Though Tengen instructs them not to stray, the three immediately leave him to look around, angering him. He explains they are in the Yoshiwara Entertainment District. Inosuke is ecstatic at the numerous people and Zenitsu becomes infatuated with the women beckoning him, causing the Hashira to chase after them to keep them on track. Tengen explains the district becomes active only at night, making it ideal for a demon to hide in.

In a house, Tengen instructs the three to look for his wife while he gathers intel on the potential demon; Zenitsu angrily refuses to cooperate, believing he is sending them out to find a bride, only for Tengen to clarify she has been gathering intel as well. When presented with the letters he's been given, Tanjiro initially thinks she had been undercover for a long time, only for Tengen to correct him by saying he has three wives, infuriating Zenitsu even more and causing Tengen to punch him in annoyance at his antics. Reading the letters, Tanjiro asks what is meant by "not to stand out". To this, Tengen informs them their job is to disguise themselves. Tengen states his first attempt to investigate the district was as a customer, proving unsuccessful. He then sent his three wives to three houses to gather information; Suma at the Tokito House, Makio at the Ogimito House and Hinatsuru at the Kyogoku House. Inosuke suddenly barks out his wives might be dead, causing Tengen to angrily punch him as well. An attendant then arrives with a box of items for Tengen.

Tengen presents the three, crudely dressed in makeup, to the Tokito house, hoping one of them would be taken in and begin the mission. Though the owners are shocked at their appearance, the house's madam happily agrees to take one in, taken aback by Tengen's handsomeness. Tanjiro, with the cover name Sumiko, is taken. Tengen scolds Zenitsu and Inosuke for the hopelessness of being put in a house, whereas Zenitsu refuses to talk, angered not at having to be dressed as a girl but by Tengen's attractive appearance. The three witness Tokito House's Oiran Koinatsu and her courtesans walking to her next client, Zenitsu asking if she is Tengen's wife. Tengen answers with a no and another punch. Inosuke is suddenly approached by a woman, a chaperone to the Ogimoto house. When asked if she is able to take Inosuke, Tengen obliges. Thus, Inosuke, with the cover name Inoko, is the second to be taken, leaving a shocked Zenitsu last.

At the Ogimoto House, Inosuke's make up is removed and the attendants are shocked at his pretty face hidden under the ugly makeup. The house is glad they had taken "her" at a low price, though they are additionaly shocked by Inoko's muscular frame. At the Kyogoku House where Zenitsu is, the demon slayer puts on a stellar shamisen performance, aided by his Total Concentration, Constant and enhance sense of hearing. The house's girls talk about "her" instrumental talent but comment on her ugly appearance, instead being smitten by Tengen, who had brought Zenitsu to the house and given him the cover name Zenko. Despite this, the house's madam believes Zenko would rise quickly, noting her performance is driven by anger "to get back at the man who abandoned her". Zenitsu, furious at Tengen's humiliating treatment of him, swears he will become the top Oiran of Yoshiwara.

At the Tokito House, Tanjiro is hard at work doing various chores. As he lifts a set of gifts to another story, he overhears some girls talking about the recent death of the Kyogoku house's madam. They also talk to "Sumiko" about 'Ashinuke', the act of a prostitute leaving her house without paying her debts over love, mentioning a recent Oiran named Suma had done so. Tanjiro suddenly remembers Suma is the name of one of Tengen's wives. Koinatsu interrupts their chat, telling them to stop spreading rumors and adding it is uncertain what became of Suma. She thanks Tanjiro for bring her gifts up to her room with an bag of orange ame-honpo candies. He tries to ask if Suma had really commited Ashinuke, causing Koinatsu to be alarmed at such a question. Realizing this, Tanjiro attempts to lie and claim Suma is his older sister, but his honest nature clashes with his lie and causes his face to contort, shocking Koinatsu and the girls. With great difficulty, he spits out he had entered the district looking for her. Tanjiro assures them Suma wouldn't have left suddenly and Koinatsu confirms this, commenting she was seemingly a grounded girl and without any hint of being in love with a man.

Tengen, rearmed and on the rooftops, scans the district for any trace. Though the area is quiet, he cannot shake the feeling of uncertainty, believing the demon they are hunting is an Upper Rank. Elsewhere, Inosuke becomes annoyed at the kimono he is forced to wear hampering his senses. While wandering the halls, he overhears some attendants talking about Makio and remembers she is another of Tengen's wives. They worry about Makio not wanting to leave her room and claiming she is unwell. Inosuke decides to head to the opposite direction of where they came; when one girl calls out to "Inoko", he doesn't respond, instructed by Tengen not to speak due to his husky voice.

Behind the door Inosuke had walked past, a woman is revealed to be tortured and bound by several long sashes. The demon asks her about the letters she is writing and who she is writing to, addressing her by her name Makio.

Anime Notes

 * The anime adds in an original scene during the events of Chapter 71 depicting the team's arrival at the Entertainent District. Inosuke can't stop running away from the group in excitement, and a flustered Zenitsu wanders off only to be called on and lured by a group of workers, causing Tengen to have to drag him back, telling him he's too young for that.