|Original Air Date||August 18, 2017|
|I Can Hear the Song of the Wind||Reminiscence: The Tarnished Mound|
"Twill" is the 6th episode of the season "Fourth Twilight" and 84th and final episode of the Hell Girl series. The episode marks the end of Ai Enma's position as Hell Girl, with Michiru Sagae replacing her, and also marks the disbanding of The Four Straws as they go separate ways at the end of the episode.
The flames of a grudge. Intense hatred became a raging curse. You committed an unforgivable sin. But you have to atone for it. As Hell Girl... That's your answer. Unable to accept her fate, Michiru teleports away from Ai, only to find herself back at the house from the last episode. Yamawaro explains that he encountered her while investigating the person who lived there. Michiru then accuses Ai of purposely teleporting her there on both times, to transform her in Hell Girl. Wanyuudou then points at a three-eyed spider. Ichimokuren asks if she saw the spider before, but Michiru denies and teleports away once again. Hone Onna then says that even if she escapes, she will be brought back, but Wanyuudou says it's only natural for her to want to escape.
At Kogure Confectionary, a girl named Yui Saitou develops a relationship with her co-worker, Tetsuya Yoshioka, all of which Michiru can see through a puddle, but tries to ignore. At midnight, Yui sees the hell mark in Tetsuya's chest and decides to access the Hell Link website, but only puts the words "Soon" on it. Yamawaro says that she's been accessing the website but only input those words on it. Kikuri then asks where Michiru is and tries to make Yamawaro forget her, but Hone Onna gets rid of her. Wanyuudou then notices that Michiru is standing on the lamp post in front of the house watching Yui and Tetsuya. Back at the bedroom, Tetsuya proposes for Yui, and she accepts it, but Tetsuya notices that she looks somewhat sad and asks what's the problem. Yui then asks him to accompany her somewhere in the next day.
At the Saihama Public Hospital, Yui introduces Tetsuya to her ill father, who is in a coma. Tetsuya introduces himself and says he will support him; however, he can, and Yui says to her father that Tetsuya is a good man. On their way back, Tetsuya asks about Yui's mom, but she replies that she died from an illness when she was young. She then asks if Tetsuya remembers her father's face. Tetsuya gets confused, but Yui tells him to stop the car and shows him where her old house is a closed Chinese restaurant. Tetsuya then remembers the incident that happened there five years ago, and Yui reveals that her old family name was Aihara. Her father was severely injured during delivery, but a street punk turned himself in 3 days later after the incident. At the trial, the punk is sentenced to 5 years of prison and is ordered to pay all medical expenses of the victim for the next three years, but Yui notices that a man with a tattoo on his chest angrily leaves the courtroom, saying that "He can't get away with this." Yui is unable to find that man, but she notices he was driving a car with the Kogure Confectionary logo on it. She then started working at the factory's cafeteria to find the person with that tattoo again. Five years passed, and she wasn't able to find the person, but one day she accidentally bumps into Tetsuya and drops coffee on his shirt, seeing the tattoo on his chest. They started going out after that, and Tetsuya angrily says that she could just have asked him about everything and wouldn't need to fool him that way, but Yui reveals that she started liking him too, with both Michiru and Ai watching the whole scene.
Back at the restaurant, Tetsuya explains they we're in five. He and his co-workers we're drunk and were walking down the alley when Yui's father accidentally bumped in one of them. Right after that, two of them started beating Yui's father, but the others were unable to do anything. Yui asks who the leader was that night, and Tetsuya responds that it was Kazuomi Kogure, the current president of their company. Tetsuya says that both Kazuomi and Suzumura, who also attacked her dad, we're out of control delinquents during high school and that they were arrested and imprisoned for assault once. Still, after being released, Kogure's connection got them both hired at the company. Tetsuya then apologizes for being too scared to move at the time, as he could have possibly saved her dad. He then says that the punk who confessed was an acquaintance of Kogure and got a lot of money from Kogure's father, the then-president of the company, to take the blame. Yui asks if Suzumura was still at the company, but Tetsuya says that he died in a car accident, leaving only one culprit left. Hiding at a pamphlet, Ai sees that Michiru was also watching the confession, but Michiru leaves when she notices Ai staring at her. Ai then says that the rest is for Michiru to decide. At midnight, Yui inputs Kazuomi's name in the Hell Link, but Tetsuya stops her right before she taps the "Send" button, saying that he doesn't want her to go to Hell too. He explains that Suzumura didn't die in a car accident, but that Hell Girl was the one who sent him to Hell on his behalf. Tetsuya had a younger sister who worked at the same company, but Suzumura raped her and threatened her in case she said anything, but Tetsuya found out in a letter she left to him before committing suicide. He then tells Yui that he's going to the police the next day, to make Kazuomi face legal justice, instead of having Yui sent to Hell too.
The next day, Tetsuya resigns from Kogure Confectionary and press charges against Kazuomi. At the same time, Yamawaro decides to leave Ai to help Michiru. At the hospital, Yui inputs Kazuomi's name in the Hell Link, and Michiru appears. Taking Yui to her Realm of Eternal Twilight, Michiru hands her a yellow doll with a red string attached to it. Michiru says that if she unties the thread, they will officially have a contract and that the person which she has a grudge against will be banished to Hell immediately. But that she will go to Hell as well after she dies. Pulling the string, Yui remarks that it was finally over. While ferrying Kazumi to Hell, Michiru tells Ai that Yui thanked her, although she was never going to be able to reach Heaven. Ai gets confused, but Michiru realizes that Ai doesn't know that Heaven exists. Back at the hospital, Yui tells her father that everything was over now, and turns off his medical devices, killing him. Tetsuya arrives in front of the hospital, only to see Yui being arrested. She then tells him that she and Kogure would go to Hell, but that at least her father would be able to go to Heaven, for which Tetsuya notices that she has the hell mark on her chest.
At midnight, Satoshi Kazama inputs his name in the Hell Link. The boy wants to go to Hell as his parents are suffering, and he thinks it's all his fault. Michiru says that he can't send himself to Hell, and that his parents are doing their best to support him and his disappearance would only make it harder for them. She then asks him to smile for the sake of his mom and dad, since smiles make people happy, and that one day they might meet again in Heaven. Somewhere else, Hone Onna remarks that Michiru accepted her fate as Hell Girl, and Ichimokuren says that he will miss it all, even after all they've been through. They also make fun of Kikuri, who is suffering from Yamawaro, as he chooses Michiru over her. Back at Yui's house, Wanyuudou wonders what is Heaven as Ai enjoys the sound of the wind chime in the house.