|Rotten Fruit||This Mundane World|
"Big Brother" is the 4th episode of the season "Three Vessels" and the 56th episode from total.
The episode begins with a normal day, when after school Yuzuki and her classmates are cleaning the classroom. The "Hell Boys Club," however, use, the broomsticks to duel each other, throwing water at every direction and causing the dismay of the rest of the class. They are interrupted by a classmate of theirs who passes between them and stating that their game is dangerous. Yuzuki recognizes him as Yukawa, and thinks of how he has changed, since a few years ago he used to be extremely shy as a person. We also have a quick scene where Ren and Hone Onna discuss their roles as teacher and suggest to Wanyūdō that he try becoming a teacher.
After the opening we see what the situation was like a few years ago. Yukawa was getting bullied every day by three classmates of his, who were making him buy them items, as well as taking money directly from him. When asked for 30,000 yen, he protested that he did not have that much and was beaten badly. Still he did not try to defend himself. He even rejected the nurse's offer to inform his teacher of the situation. During winter we see him tied on a tree, without wearing any clothes and getting thrown snowballs by his bullies.
As one is about to shoot him in the face with a snowball and a rock hidden inside it a man in a fighting uniform steps between them and redirects the snowball to the bully's shoulder with a wooden sword's swing. The bullies attack him enraged but are quickly beaten and run off. The man unties Yukawa. Later when his savior asks him of if he has any relation with the famous fighter Yamato Takeru, Yukawa answers that his family forbids him of shaming that name. Nishida tells Yukawa that he's in the kendo club and that his dream is to become a prosecutor in the future, so he can fight criminalism.
Later in a restaurant, Nishida suggests that Yukawa starts kendo, but Yukawa answers negatively, explaining that he has gotten used to bullying and that this is how society works. After a few months in which Yukawa becomes friends with Nishida, he watches Nishida winning matches in duels. Impressed he congratulates Nishida, and through their talk Nishida manages to convince Yukawa to start training with him. The training goes well.
Back at home Yukawa's family is impressed and happy with the change, and the rest of the family members even suggest that they should somehow thanks Nishida for the change in Yukawa. After that we go to the present, when Yukawa is a lot more popular than he was and the bullies get out of his way. After a usual meeting between the nurse and Yuzuki, the nurse asks Yuzuki how Yukawa has been doing lately. The fact that Yukawa was being bullied accidentally slips through the nurse's mouth. Yuzuki leaves troubled.
In the bus where Nishida and Yukawa sit next to each other Nishida has stress for the exam but Yukawa manages to relieve him of it. The bus driver instantly presses the break as he is about to hit a young girl riding her bike. Kikuri asks a nearby driver to wind her up and then leaves. Weather or not Kikuri being there was accidental is unknown. A passenger on the bus gets up from his sit. His looks is offensive and he seems dangerous. When another passenger complains about getting hit in the head the first passenger threatens him with a knife. For the rest of the ride he keeps cutting hair from the unlucky man with the rest of the passengers trembling. Enraged Yukawa gets up but a look from the armed man is enough to make him sit down again. As Yukawa looks next to him he sees Nishida shaking in fear.
In the bus the armed man forces the driver to pass a stop where Yuzuki and Akie were waiting. Akie bursts into a comical crying. In the bus the armed man has made the unlucky passengers hair round-cut, and the passenger is forced to thank him for that. In the stop the armed man needed he gets off the bus forcing the unlucky passenger to follow him. The rest of the passengers are terrified and the bus driver is relieved that the bully-passenger has left.
Nishida lies to Yukawa that he didn't act to such obvious criminalism because Yukawa was there, but Yukawa sees through it and is enraged. Nishida runs away. Yukawa contacts Hell Correspondence and is given Ichimoku Ren's doll. Yuzuki sees the whole procedure via a vision. Immediately after Yukawa pulls the string. Once again Yuzuki loses control of her body and Emma takes over.
In the foretelling of his punishment Nishida is forced by Emma's assistants to keep hitting a Kong. The whole process requires a lot of muscles and is tiring. Nishida begs for another chance but Emma appears. We next see Ishida in the boat that sends him to hell, crying because he was the only one from the passangers that was punished. A few days later Yukawa has stopped kendo and is getting bullied again. He answers to the nurse's question on why he stopped that even if he changed a little, nothing at society would change, and even smiles with that statement. The hell-bound tattoo has appeared on his chest, and by his smile it is clear that he is happy with Nishida being sent to hell.