Jyugo, Uno, Nico, Trois are attacked by Ruka’s powerful weapon, Bashosen. Honey tries to fight him off, but at this rate, all four will perish. Trois tells Jyugo and Uno to go ahead of them while they fight Ruka. Uno takes Jyugo’s hand and run towards the stairs. But Jyugo is concerned about Honey and Trois who are fighting for them...

Jyugo and the others continue to run from Ruka’s attack. But Honey tells Jyugo not to follow them because he believes Jyugo’s only in their way. Jyugo starts to self-reflect from Honey’s lecture and starts revealing about himself to Uno. However, Ruka is quickly approaching. Jyugo and Uno are saved by someone unexpected.

Beating Hachiman, Nico, Liang, and Upa moves ahead guided by Qi. Upa feels someone other than Enki is involved in the incident. Jyugo, Uno, Honey, and Trois reaches level 3 underground. They encounter Ruka Gojyou, a former Building 5 guard who has escaped from his cell. Ruka, along with guards, Youriki and Kokoriki, attacks Jyugo’s party. Running away from Ruka, Honey starts getting irritated at the incompetent Jyugo.

The medication completely gone from his system, Nico suffers and goes berserk. Wanting his medicine, Nico attacks Hachiman. Upa and Liang is surprised to see Nico in that state. Then, the traitor, Qi, appears. Qi understands medications can turn into poison if they’re not handled properly. He remembers the days when Hachiman used to treat him like a tool along with Upa and Liang.

The escaped convict, Hachiman, appears in front of Liang and Upa. Nico has remained with them to help. Hachiman, former boss of Liang and the others, uses a large weapon and poison to attack. That poison was provided by Qi, who has betrayed Building 5 and joined Hachiman. Meanwhile, Uno and Jyugo are concerned about Nico, who doesn’t have his medication. It seems something horrible will happen to Nico is he doesn’t take his medicine...

The inmates in Cell 13; Jyugo, Uno, Niko, and Rock are spending their days escaping, creating mischief, gossiping, and sometimes, working. These troublemakers are giving a headache to supervisor of Bldg. 13, Hajime Sugoroku. Warden Hyakushiki has ordered Hajime to submit files regarding the 4 inmates. Hajime is then ordered to give a report about the 4 who are known as repeat offenders of jail-breaking. Afraid of losing his job due to the cover-up, Hajime does his best to create the new files...

Jyugo, Uno, Nico, Liang, Upa, Honey, and Trois make their way through Building 5 underground cell to find the captured guards. They hide in the file room and Jyugo finds document about himself and finds a shocking information. The group encounters a Building 5 guard, Rokuriki, who is under someone’s control. Liang and Upa tells Jyugo to keep going while they take care of Rokuriki.

Hajime, Jyugo, Uno, and Nico head to Building 5 to find out about Rock and Yamato. Jyugo and the others fall into a trap and end up in level 1 underground cell. There, they find the captured Upa and Liang. Meanwhile, Hajime is captured by Inori and is escorted to the underground cell where Samon, covered in injuries, is restrained. Samon reveals who’s behind the incident. It is no other than Enki Gokuu, the former Building 5 supervisor who became a criminal causing havoc in Nanba Prison in the past. He is also Samon’s brother.

Rock and Yamato suddenly become violent after returning from Building 5 and attack Jyugo and Seitarou. Covered in bruises, Jyugo tries his best to protect Uno and Nico. Tsukumo, who has been training in Building 5 with Rock, appears. Hajime knocks out Yamato and realizes a familiar yellow talisman on the nape of Yamato’s neck.

Yamato takes Rock and Tsukumo to Building 5 for training. Rock challenges Samon to a duel, but he is defeated by only one finger. The warden gathers all the supervising officers before she leaves for her business trip. Nimaijita, the deputy supervisor of Building 2, blames Samon that Nanba Prison’s reputation is ruined because of what happened in Building 5 in the past. Unable to take it any longer, Samon leaves the room. This is because someone important to Samon is related to this incident.

A new guard has come to Building 13. It’s Hajime Sugoroku’s brother(?), Hitoshi Sugoroku. This takes Hajime by surprise and he tries to lecture Hitoshi to go home, but he has already been hired. Meanwhile, Uno and Rock starts doubting Hitoshi, who can pull off a woman’s guard clothes nicely, is actually a gorilla’s... or Hajime’s brother. To find out the truth, the 2 announce the beginning of Cell 13’s customary game of tag.

Jyugo escapes from prison again and Hajime Sugoroku goes looking for him again. Uno, Nico, and Rock are having a good time in Building 13. It’s a usual day for the inmates and guards. Many things have happened, but it seems like nothing has changed in Nanba Prison. But don’t let your guard down! Mitsuru Hitokoe, sensing a disturbance in the air, goes spying on each building believing something will happen.

A man name Elf suddenly appears in front of Jyugo. Elf has connection with the man with the scar on his neck and has been looking for the specimen, Jyugo. Elf conveys that he will harm the people around Jyugo and disappears. Jyugo fears that something bad might happen to his friends if he stays, so he decides to escape from Nanba Prison alone.

Kenshirou visits Musashi in Building 4’s underground cell to ask about his past. Building 13 invites Musashi to come visit. Uno shows Musashi his new game room. All the inmates and guards who fought in the New Year’s Tournament gather in the game room. They enjoy each other’s company putting their animosity behind them. That night, Jyugo can’t sleep still excited from the day’s events. He escapes the cell alone and encounters a certain person...

Building 13 Cell 13 has won the New Year’s Tournament. Rock receives a stone oven and Nico receives the latest video game everyone can play with. Rock and Nico invites inmates from other cells to show their prizes. The two are very satisfied and they both thank Jyugo for that.

Hajime has been given a three-day suspension due to beating Jyugo at the New Year’s Tournament. Momoko orders Kenshirou, Kiji, and Samon to take turns covering for Hajime. But Uno, Nico, and Rock do whatever they want as usual. The three supervisors constantly struggle to maintain order with the three troublemakers. Finally, after three days, Jyugo is back...

This is “Nanba Prison,” the large impregnable prison somewhere in the territorial waters of Japan. On this night, 4 inmates recklessly attempt to escape from the world’s best prison guards and security. Jyugo, who wears mysterious shackles. Uno, a self-proclaimed ladies’ man. Niko, an otaku who’s prone to illness.Rock, a foodie gang member. Can the inmates of Building 13, Cell 13 pass security and reach outside of prison in one piece?

As part of a special test, the school has brought the students to an uninhabited tropical island where they must now live for a week. Their performance on the test can have an enormous impact on the point standings of the four classes.

It's summer vacation! The first-years get to board a luxury cruise ship, where they're allowed to sample the highest class facilities available.

Even during summer vacation, lone wolf Horikita would rather remain locked in her room studying than interacting with others. One day, Ayanokoji invites her to visit the pool with some of the others.