Marriage Toxin - Episode Guide

The highest rank in the assassin industry, the "user," is Gero Hikaru, the next head of the Gero family, the "poison user" family, which possesses top-class power. Living a life in the underworld and avoiding contact with women, marriage is an impossible prospect for him. However, his grandmother, the current head of the family, informs him that in order to prevent the "poison user" bloodline from dying out, his sister Akari must bear an heir. Determined to protect his sister, Gero Hikaru decides to get married, and unexpectedly proposes to Shirosaki Mei, a highly skilled con artist he met while she was his target for an assassination...!? Thus begins the strange marriage-hunting mission of this assassin and con artist duo.

Gero's search for a wife begins with marriage swindler Shirosaki as his advisor. Shirosaki, who claims he can charm any woman in 30 seconds, insists that the best way for Gero to find love is through "helping people." Gero wonders, "How can a hitman help people...?" Shirosaki suggests using an underworld job matching website. One day, a painting theft occurs on a luxury cruise ship that the two are visiting for a rehearsal of their date. There, Gero meets Himekawa Kyoko, a notorious art thief in the underworld.

Gero, who has taken on the task of rescuing Himekawa, engages in a fierce battle with the "Water User." Himekawa, who steals works of art, has a specific purpose: to return the works of art to their rightful owners. Can Gero win the battle between the "Users" and help Himekawa achieve her true objective as part of Shirosaki's "Prince Charming Plan" for finding a husband? Then, Gero begins by saying, "I have a favor to ask," and makes a proposal to Himekawa as the first step towards a happy marriage.

Gero's new job is to be the bodyguard of Ureshino Shiori, the daughter of the president of a major corporation. Gero infiltrates the university Ureshino attends, posing as a fellow student. Having never attended university before, Gero's eyes light up as he participates in parties and classes, experiencing a life full of firsts. However, his enjoyable campus life is short-lived, as Gero and his companions are ambushed by assassins targeting Ureshino. While they manage to protect Ureshino and continue their student life, Naruko Genya, the "sound user," is steadily making preparations to assassinate Ureshino...

At a university training camp, Shirosaki hopes to use the "suspension bridge effect" to find love during a test of courage. However, as soon as he and Ureshino head out for the test of courage, Gero finds himself confronting Naruko, the "sound manipulator." Naruko, who has laid traps throughout the entire test of courage, cunningly tries to kill Ureshino while fighting Gero. The succession struggle began when Ureshino was nominated as the next president. Who commissioned Naruko, the "sound manipulator," to kill Ureshino? Will Gero be able to protect Ureshino safely?

The students are thrown into a panic by the rumor of "Kuradoni-sama," a ghost story invented by Naruko. In their rampage, they nearly offer Ureshino as a sacrifice to "Kuradoni-sama." The only way to stop their rampage is to stop Naruko. Ureshino, who had been escaping with the help of Shirosaki, decides to take matters into his own hands to protect his friends. Can the shy and introverted Ureshino overcome himself and grow? And with determination, Ureshino makes a request to Gero.

Gero and Shirosaki are invited to the wedding of "Insect User" Toshiki Hanamaki. Shirosaki grins, saying, "Weddings are places where people meet." Also present at the wedding is Tsunagu, a friend of Gero's and a father of three, known as "Needle User." While a happy atmosphere hangs in the air, Yuji Yamada, who holds a grudge against Hanamaki, arrives with mercenaries, intending to disrupt the ceremony. Yamada plans his revenge against Hanamaki using his "Five-Body Explosive Fist," which involves small bombs embedded in both his wrists, both ankles, and his head. Gero, along with Hanamaki's partner Julia Jr., entrusts Shirosaki with the best man's speech and runs off to protect his best friend's wedding.

Following Shirosaki's advice, Gero continues his search for a wife. He is asked by Arashiyama Kimie, a "hamster user," to protect her from "assassin hunters" because, despite being a "user," she is not good at combat. Overwhelmed by her enthusiasm, Gero agrees. Shirosaki seems hopeful that Gero and Arashiyama might get along surprisingly well since they are both "users." Later, Gero and Shirosaki are taken by Arashiyama to a gathering of collateral branches of the "beast tamers." There, Gero confronts Nakagawa Momoichi, an assassin hunter and a mutant ordinary person with combat abilities that surpass even top-class assassins. What exactly is his objective...?

Gero's search for a wife begins with marriage swindler Shirosaki as his advisor. Shirosaki, who claims he can charm any woman in 30 seconds, insists that the best way for Gero to find love is through "helping people." Gero wonders, "How can a hitman help people...?" Shirosaki suggests using an underworld job matching website. One day, a painting theft occurs on a luxury cruise ship that the two are visiting for a rehearsal of their date. There, Gero meets Himekawa Kyoko, a notorious art thief in the underworld.

As Arashiyama and Gero head towards the enemy's headquarters together, Gero proposes that they defeat the "Beast Tamer" together. While planning their strategy in a cave where they take refuge for the night, the two grow closer, but the atmosphere changes abruptly when Toshiro appears. Toshiro then hurls words that fuel Gero's murderous intent and takes Arashiyama away. As Gero pursues them, he is attacked by 100 of the "Beast Tamer's" associates, strengthened by Toshiro's "mixed blood." Outnumbered and exhausted, Gero is then confronted by "reinforcements" arranged by Shirosaki…

Shirosaki and Momoichi are separated from Gero and the others. In the forest, the two find the headquarters of the "Beast Tamer" and, upon entering the laboratory, witness Jushiro conducting experiments with blood test tubes in his hand. Momoichi engages in a fierce battle with Byakko, a hybrid beast created by Jushiro, but is put in an unprecedented predicament by Byakko's immense power, which has incorporated the blood of Gero and Momoichi as well. Gero, who is once again confronted by Jushiro, suffers an overdose from "Toxin Triple." Meanwhile, Arashiyama, whose life is in danger, grits his teeth and summons all his strength to take action.

Having overcome the overdose caused by "Toxin Triple," Gero confronts Jushiro with even greater power. In a battle between the five noble families pushing each other beyond their limits, Gero finally reaches the essence of a "poison user"—the ultimate secret technique, "Poison Blood Dissociation." Meanwhile, Arashiyama and Sirius are about to carry out a certain plan, leading the collateral branches of the "Beast Tamers" who had been captured and imprisoned by Jushiro. The duel with the "Beast Tamers"...the final showdown is finally here!

The fate of Jushiro and the white fox is entrusted to Dogo Jushiko, the head of the "Beast Tamer" family. Meanwhile, Arashiyama holds the "Animal Thanksgiving Festival" to express his gratitude to Gero and the others. Gero finds Arashiyama's way of life truly admirable. Shirosaki, not wanting to miss this chance for romance between the two, activates her love-assist skills! What will become of Arashiyama and Gero's love...? Gero's search for a wife accelerates after meeting Himekawa, Ureshino, and Arashiyama. At the same time, Gero Teruaki, a member of a branch family of the "Poison Tamer" Gero clan, seems to be making some ominous moves...