First Nin - Shinobi Returns!!

First Nin - Shinobi Returns!! is the first episode of Hero Retold: Kamen Rider Shinobi. It features the debut of the new monsters in the series; the Nin-Ju.

Continuity
While the background information regarding Kamen Rider Shinobi happened between 2022 and 2024, the events of the first episode actually take place in the New Year of 2025.

Plot
2024, two years after the government made provisions to the Ninja Act, Iroha Kagura has since been employed by the Konjo Group, which has grown as a multinational conglomerate due to their multiple sustainable environment actions. At the 2025 New Year’s countdown party by the Konjo Group, Iroha celebrates with the other employees, when a workmate Mina asks her about Rentaro’s whereabouts. While the others sing karaoke, Iroha simply answers that he’ll be busy with his job, especially this holiday season.

At the same time, the Niji no Hebi’s base of operations is attacked, with numerous Ninja Dustards being defeated and destroyed. As the Yaminin leader tries to escape with numerous scrolls, he is confronted by Kamen Rider Shinobi, who engages and defeats him. As the Yaminin gets knocked down, one of the scrolls unroll, revealing the important lore:

''Two thousand years ago, the red waters of the Sanzu River overflowed from the hills of dread, causing a massive eruption that caused heavy rains for three days and three nights. As the waters are not of this world, the storm caused much destruction and death. With the need to stop the ravaging waters of the afterlife, the royal family of artisans conjured seven vessels to collect these waters and save humanity.''

The scene cuts to the next day, where Rentaro reads through the text of the scroll, only for Iroha to chastise him for not getting paid with his job last night. Rentaro retorts that the scrolls were more than enough payment, since he could learn more about ninjutsu and its history, only to be told off by his sister, saying that he should also path of the ninja, like her, before leaving to go to work, Master Gamano tells Rentaro not to worry about Iroha, since she’ll be much safer now that she’s no longer risking herself, while also congratulating him for finally defeating Niji no Hebi once and for all. Rentaro seconds this and reassures himself as well since she’s now protected both by him and Icchy.

Meanwhile, at the Konjo Group, Isamichi has finally stepped up as the Vice-CEO of the company. While trying to manage the group’s upcoming projects, a disgruntled former employee named Matsubara forces his way to the office-grounds and airs his grievances for being fired. He also mouths off to the employees that were hired despite not having ninja abilities. Isamichi reprimands him publicly, saying that he abused his abilities as a ninja just to get perks and that the abuse of privilege also got him fired. Matsubara then uses his ninjutsu to overpower the guards holding him back and lunges toward Isamichi. He, however, was quickly subdued by Ayane, the company secretary and Isamichi's assistant. As Matsubara is being escorted by the security, Isamichi tells Ayane that he could’ve handled the situation by himself, but Ayane reminds him that he now has more important tasks to do as a Vice-CEO and has no time to “play ninja”. She then gestures towards Iroha approaching them, as Iroha greets him to start the day.

While Rentaro is riding his motorcycle on the streets, he passes by the police car escorting Matsubara and feels a negative presence. He pulls out his phone to talk to Master Gamano on its screen about that bad feeling, but a shuriken flies past barely hitting him. Rentaro stands guard before noticing a note lodged on the shuriken. He goes back to his home to look at the scroll once again, this time, with a shocked expression. That night, Rentaro climbs up on a roof and sees as the moon turns blood red, while also seeing red aura enveloping the city. He then looks at his Hyoutan and as it glows, he mutters “so it’s this year, huh?” In a prison cell, Matsubara grins and breaks his handcuffs, repeating his anger towards the Konjo Group. As he looks at the red moon, water pours out of his body and envelops him, transforming him into a Nin-Ju.

The next day, the Nin-Ju attacks the Konjo group office, injuring several employees while screaming “Konjo!”. Isamichi comes out and tries to help his employees get to safety. Ayane also tries to fight off the Nin-Ju but the monster easily shrugs her and attacks her, only for Isamichi to grab her off to safety. Isamichi jokingly says that “now’s the time to play ninja”, as Ayane reluctantly hands him his gold hyoutan. Icchy transforms to Kamen Rider Hattari and battles the monster inside the office, initially gaining the upper hand, but the beast gets angrier and sees Iroha. The monster tries to get her as leverage, but in time, Kamen Rider Shinobi breaks in and guards Iroha and he also battles the monster to submission. When Hattari sees an opening, he tries to go for the killing blow, only for Shinobi to push the Nin-Ju back and block Hattari’s attack, confusing both Iroha and Isamichi.

Fan Casting

 * Rentaro Kagura: Hideya Tawada
 * Isamichi Konjo: Takuma Zaiki
 * Iroha Kagura: Asuka Hanamura
 * Master Gamano: Nobuo Kyō
 * Ayane Suzume: Kana Oya
 * Mina: Reiko Fujiwara
 * Tsunayoshi: Ataro Dojun

Guest Cast

 * Matsubara: Eitoku

Suit Actors

 * Kamen Rider Shinobi: Yuji Nakata
 * Kamen Rider Hattari: Shogo Teramoto
 * Gray Nin-Ju: Eitoku