"Eternal Party" is the last episode of the Toaru Kagaku no Railgun S anime adaptation, and the 48th episode of the Toaru Kagaku no Railgun animated series overall. The script was written by Yoshino Hiroyuki and directed and storyboarded by Konno Naoyuki. The episode's animation was co-directed by Tomioka Hiroshi, Kumagai Katsuhiro, Sato Marina, Sakai Satoshi, Komatsubara Sei, Kimoto Shigeki, Naoya Takashi, Ishii Tetsuya, Tanaka Yuichi, and Hiyamizu Yukie.
Now STUDY has shown its power in the sleepy hours of Academy City, but awaits them will be beyond their preparations and expectations, as the forces of Mikoto of her friends, esper and powerless, gather in force to thwart STUDY's plans. And now, the finale of Toaru Kagaku no Railgun S begins!
STUDY finally mobilizes their "revolution". Nunotaba Shinobu can only recall her memories with Febri while wondering if she has made the right choices back then, as STUDY pushes through their plans. Meanwhile, STUDY confidently marches on despite the presence of a few "gatecrashers" in their party...
...only to be shocked at the presence of hundreds of Judgment operatives, parading their green armbands and their will to fight those who seek to disturb the peace of Academy City.
As a resounding "JUDGMENT DESUNO (I'm with Judgement)!" echoes throughout the Academic Assembly venues (much to Kuroko's surprise), Mikoto heartily laughs while on her way to track down Janie's position.
Soon, Judgment begins their offensive. Kuroko uses javelins instead of her usual metal spikes to cripple the Powered Suits, while Judgment employs various tactics to exploit the simple commands given to the Powered Suits, from power by numbers to hit and run tactics to keep the unmanned Powered Suits busy. Meanwhile, those with capable offensive abilities, like Kongou Mitsuko and Shirai Kuroko, finish off the preoccupied enemies.
STUDY decides to increase the power output on Janie from 2% to a much higher value, however, Mikoto has already found Janie's whereabouts, causing STUDY to set their sights on the traitor amongst them, Nunotaba Shinobu. Later, Aritomi "welcomes" Mikoto to their main headquarters and prepares hundreds of Powered Suits to take her on, confident that Mikoto would succumb to fatigue after long periods of fighting alone. To Aritomi's shock, however, Mikoto was able to destroy a large number of Aritomi's units using her abilities, including the Railgun.
Aritomi quickly changes plans upon seeing Mikoto's display of might. As he jams the signals of all electronic devices at the four Academic Assemly venues, he deploys larger mechanical units, piloted by two of Aritomi's associates, to take care of the Judgment forces. Chaos quickly throws the Judgment forces into disarray, while Mikoto is already feeling the effects of fatigue as more and more of Aritomi's Powered Suits arrive to slow down her advance. To make things worse, Aritomi has also deployed three advanced mechanical units which imitate the ability of the Meltdowner, Mugino Shizuri.
Uiharu and Ruiko are forced to retreat in the midst of STUDY's new units, and Uiharu became close to becoming a casualty in the chaos. Suddenly, a much larger unit that dwarfs those of STUDY arrives on the scene, where Yomikawa Aiho and Haruue Erii are onboard. Erii then tells everyone that a telepathic connection is being set up to compensate for the lack of communications devices, care of Edasaki Banri and the telepaths of Judgment.
Ruiko and Uiharu soon enter the large vehicle that came earlier and Ruiko accustoms herself to the controls, which she had well prepared the night before. Soon, as Mitsuko proudly introduces Kongou Airlines' all-purpose transforming robot she calls "Ekaterina II-S", Ruiko and Uiharu join forces in swiftly taking down STUDY's advanced mechanical vehicles.
In Mikoto's front, the Rank Three Level 5 is surprised upon seeing another Level 5 in the battlefield: the Meltdowner herself, Mugino Shizuri, instantly destroying her copycats using her ability. Soon enough, ITEM regroups and Frenda and Kinuhata Saiai help turn Aritomi's robots into scrap metal while allowing Mugino to unleash her fury upon realizing that she was used as a data source by STUDY. As ITEM destroys what's left of Aritomi's forces, Mikoto takes the opportunity to sneak into STUDY's main headquarters.
STUDY's plans are slowly breaking apart. And to make things worse for them, Mikoto has arrived to confront Aritomi. However, Aritomi has decided to resort to drastic measures, shutting down Janie's link with the many Powered Suits outside to turn Janie into an unstable entity. Then, Aritomi prepares to end his life, leaving behind Janie in her unstable state and Febri without the neutralizer that would prolong her life.
But, Mikoto refuses to let Aritomi do what he wants. Using her electricity, she stops Aritomi from shooting his head and slaps him with her left hand, injured by her sudden contact with the pistol while firing. There, Mikoto points out that she knows a lot more about the darkness than him, and despite that, she would still save everyone, even the man in front of her who has just attempted to cause widespread chaos just to make a point.
Aritomi is frozen stiff as Mikoto demands the commands needed to reverse his "last resort", but Aritomi's colleague, Sakurai Jun, explains to her that they are in a grave situation, as Aritomi's last resort involves releasing thousands of filaments from a missile fired 35,000 kilometers above the Earth, and the rampaging Diffusion Ghost will cause widespread AIM diffusion field interference that will affect each and every esper in Academy City.
Mikoto accepts that she cannot do such a feat by herself, and so she decides to ask help from her friends.
After Mikoto has told the others about the missile that is heading towards Academy City at 420 kilometers per hour, Uiharu quickly steps into action, attempting to locate, track down and determine the missile's trajectory. However, she feels that she needs a faster computer to perform the calculations needed to pin down the missile's coordinates. To make things more tense for Mikoto, Febri's last lollipop is gone, and the poison in her system would damage her body soon. Shinobu decides to do what she can to prolong Febri's life, while Mikoto's "little sisters" decide to help in pointing out the trajectory of the incoming missile.
Most of the Judgment have decided to take a break to regain their energy. Meanwhile, Ruiko runs to Mikoto's whereabouts to hand over Febri's bag, where there are still some lollipops for Febri to eat. Shinobu then begins her attempts to restore Janie to a more stable state, which she thinks would require a strong emotion to work... "like love", as Ruiko suggests.
Mikoto and Kuroko reunite at the Ekaterina II-S and are now the new pilots of the machine. Mikoto, with the help of her clones, finally determines the whereabouts of the missile and prepares for an aerial confrontation. Mikoto then asks pardon from Kuroko for having her participate in such a dangerous, only to be touched by Kuroko's happiness of finally being able to help her Onee-sama. The Ekaterina II S then launch into space in a warhead-esque fashion, with the help of Mitsuko (who had previously placed 8,092 air ejection points to launch the mech) and Maaya (who severely reduced the mech's weight by increasing its buoyancy). Meanwhile, Shinobu gambles on Febri's love for her newfound friends to reach Janie... only to discover the love the Sisters Clones have developed due to Shinobu's intervention in the Radio Noise Project.
The Misaka Clones use their combined calculation powers to boost the systems Shinobu is using to restablize Janie. Meanwhile, several thousand feet above, Mikoto and Kuroko step out of the Ekaterina II-S, with Kuroko stepping aside as Mikoto uses all of her might to launch the entire machine into the missile like a railgun. In an instant, the missile and the Ekaterina II-S were destroyed, leaving behind Kuroko to lead Mikoto to a safe landing down on Earth.
Meanwhile, after much anxiety, Janie finally wakes up from a long slumber. After greeting her sister, Febri hands over a rice ball to Shinobu. At that moment, Shinobu is relieved to tears after having finally redeemed herself and having saved what she was unable to long ago.
Later that day, the Academic Assembly kicks off once again. Shinobu leaves for overseas so that Janie and Febri would undergo the procedures needed to stabilize their bodies, and as Uiharu and Ruiko make their tearful goodbyes to Febri, Mikoto voices out her disappointment over Shinobu needing to leave so soon. Shinobu also mentions how a lot of people seem to have forgotten the events that happened earlier, leading Mikoto to think about a certain Level 5 more than capable of doing such a thing.
Soon, Shinobu tells Mikoto that it is her turn now to take care of Janie and Febri, and that she will do her best for their sake.
Shinobu, Janie and Febri soon leave aboard a Kongou Airlines flight, leaving behind Mikoto, Kuroko, Uiharu and Ruiko to prepare for their afternoon classes... and the Liberal Arts City field trip the following day?!
- STUDY's nefarious plot has been stopped and Janie and Febri are free of their bondage.
- The Academy City Research Exhibition Assembly of the year begins.
- Shinobu, Febri, and Janie leave Academy City.
The content of this episode is completely original, and as such isn't adapted from any pre-existing material.
- Nunotaba Shinobu
- Misaka 10032
- Misaka 19090
- Misaka 10039
- Misaka 13577
- Shirai Kuroko
- Konori Mii
- Kongou Mitsuko
- Wannai Kinuho
- Awatsuki Maaya
- Uiharu Kazari
- Saten Ruiko
- Aritomi Haruki
- Sakurai Jun
- Sekimura Hirotada
- Yanagisako Aomi
- Misaka Mikoto
- Mugino Shizuri
- Kosako Shunichi
- Madarame Kenji
- Yomikawa Aiho
- Haruue Erii
- Edasaki Banri
- Kinuhata Saiai
- Frenda Seivelun
- Takitsubo Rikou
- Shokuhou Misaki
- Ringlet curl girl
- Last Order
- Tessou Tsuzuri
- Heaven Canceller
- Kamijou Touma
No new characters were introduced during this episode.
- Academy City
- School District 7
- School District 23
- A Certain High School
- Liberal Arts City (referenced)
No new locations were shown during this episode.
- Diffusion Ghost - Janie, Unknown Level.
- Teleport - Shirai Kuroko, Level 4.
- Electromaster (Railgun-variant) - Misaka Mikoto, Level 5.
- Hydro Hand - Wannai Kinuho, Level 3.
- Aero Hand - Kongou Mitsuko, Level 4.
- Telepathy - Edasaki Banri, Unknown Level.
- Meltdowner - Mugino Shizuri, Level 5.
- Offense Armor - Kinuhata Saiai, Level 4.
- AIM Stalker - Takitsubo Rikou, Level 4.
- Accelerator - Accelerator, Level 5 (flashback only).
- Radio Noise - Sisters, Level 2 or 3.
- Mental Out - Shokuhou Misaki, Level 5.
- Float Dial - Awatsuki Maaya, Level 3.
- This is the first actual time Aomi is shown to be on duty as Judgment.
- The full capabilities of Mitsuko's Aero Hand is shown for the first time.
- The mechas that uses Shizuri's Meltdowner may be a reference to the FIVE_Over series.
- Aritomi is shown to be try and attempt suicide via a gun to the head. However, in the original manga, Kiyama Harumi was shown to do the exact same thing once her plans became unraveled and when the AIM Burst started its rampage. It is unknown why Harumi's attempted to suicide was taken out.
- Misaka 19090 is revealed to be the clone that was in the Testament machine as she tried to inject emotions into the Misaka Network.
- only my railgun is the only opening not used as an insert song this episode.
- Shinobu is shown wearing a gothic lolita outfit for the first time in the present day.
- The denouement scene shows that Mikoto has changed her hairpin (from the previously plain one to a floral one), implying that Janie, Febri and Shinobu's departure occurred after August.
- Accelerator and Last Order are shown with both of them conscious. These further supports that the end of the episode occurs way after August.
- Touma is shown to be doodling a drawing of Index on his notebook.
- After the departure of Febri, Janie, and Shinobu they mention that the Liberal Arts City trip is the next day, which suggests that their departure occurred during September 2, a day before the Mikoto and company arrive at Liberal Arts City.
- Banri wanting to join Judgment from episode 18 is referenced again.
- The riceballs Ruiko and Kazari made last episode are shown being eaten this episode.
- Kuroko uses javelins for the field athletics known as javelin throw as her main weapons during this episode.
- The scene where Ruiko is shown studying "something" related to Kongou Airlines is used as a flashback this episode.
- Scenes from episode 05, 14, and 15 are reused as a flashback regarding Accelerator.
- The explosion of the missile in the upper atmosphere/space is the exact animation used for sun-rising sequence in the second opening.
- Where did Aiho go to after Ekaterina II S transformed?
- How was STUDY able to put a missile up on Endymion's orbital station?
- What did Mikoto ask of Misaki to have her tamper records for her?
- Where are Shinobu and the twins going to for the twins' readjustment?
- Judgment members: "This is Judgment!"―to STUDY.
- Kuroko: "Come one, come all! Through these gates, I, Onee-sama's herald, Shirai Kuroko, shall not let you set one foot!"
- Mitsuko: "Do you think I'll let you lay a finger on my friends? You're a hundred years too early!"
- Kuroko: "I'm not the same Kuroko you're used to seeing. Because... I'm fighting... alongside Onee-sama!"
- Mikoto: "If I were alone, maybe it'd be rough. But... I'm not alone anymore. Everyone's... fighting alongside me!"―to Haruki.
- Mitsuko: "Allow me to introduce you to the general-purpose transforming robot, built by Kongou Airlines' Second Academy City Factory using all of our technical expertise!... Introducing... Ekaterina II S!"
- Ruiko: "Whoa, Uiharu! I see you're in a fiery mood today!"―to Kazari after looking at her panties.
- Haruki: "Spend your final moments c-cowering in fear!"―to Mikoto.
- Mikoto: "Dying and avoiding responsibility? You're not getting off that easy. I know someone who was already too strong, and still tried to become stronger. I know people who despise not having any powers, just like you, who did inhuman things, trying to get them. I know people who thought that they were just puppets, and silently accepted a cruel fate. And I know a complete idiot who thought that they could just die, if that's what it took to protect them. But who's stronger or who's weaker, who comes out on top or on bottom... None of that matters. I promised everyone. To save Febri, no matter what. To protect this city. And if it's what it takes, I'll save you too!"―Mikoto's speech to Aritomi Haruki.
- Shinobu: "I'll handle it. It's not about whether I can or can't, is it? I'll do it. Like you said, what only I can do."―to Mikoto upon hearing that Febrie's has expended her lollipops.
- Ruiko: "I see. So basically, the power of love?"―to Shinobu upon hearing her explanation on how to wake Janie.
- Misaka 19090: "Thank you for giving me a heart."―to Shinobu.