When Hotaru moves into a new apartment alone, there's a mysterious man standing nearby the apartment. Hotaru decides to confront the man, who turns out to live in the neighboring apartment. The next day at school, Hotaru's best friend Kanae tells Hotaru that a host tricked her out of her money. When Hotaru goes to confront the host, he happens to be none other than Hotaru's neighbor, Masamune?!
Hotaru Tachibana, a lively headstrong student council president, meets a strange mysterious man on her way home, waiting by her apartment door. On learning that her best friend was conned by a Host, Hotaru goes over to the Host club to deal with the person in question, who in turn challenges her to a Gun game called "The Survival Game".
Toru Yukimura, an S&M ero-manga artist is introduced as the third member of "Team Toy Gun Gun". Yukimura seems rather displeased with his new team mate, but will they manage to pull it off and win as a team despite everything?
The black envelop is a special invitation given to a chosen few who have earned the right to be in a special Survival Game tournament, those given to the members of Team Toy Gun Gun and to a certain man dressed in a white lab coat, who works as a pediatrician.
Yukimura clashes with Midori, as some past issues concerning Masamune and their past feuds were brought up. Caught in a rifle accuracy test which she fails at, Hotaru goes up against the gun store manager as her last resort to win her G3 SAS gun.
Hanako was asked by Masamune for Hotaru to join her team instead, for the day. Later on Hanako found out why Masamune wanted Hotaru to know more of the basics to the game, to bring out the hidden talent that Hotaru may have.
A competition is starting soon, Hanako is surprised by how many are competing in it. While as others plan ahead.
Hanako's team is up and everyone is splitting up to their places. Then Hanako sees Fujimon what will Hanako do?
Round One of the Top Gun Combat competition continues. With Fujimon out of the match, team Toy Gun Gun and duo Midori and Ichi remain. Matsuoka, Yukimura and Tachibana each have a turn fighting Midori. The winner of the first match is determined.
Hotaru is resting at school, when Kanae wonders why and asked? As Hotaru felt down when the match ended, in a lost. Later Kanae wonders if Hotaru just quits? Then Kanae looks at her phone she knows what is it about, and what Hotaru does in the games she plays in.
Masamune kicks Hotaru out of the team, giving her the reason that she's too weak. In order to prove her worth, Hotaru challenges Nagamasa Midori in a one on one fight.
After the challenge, Hotaru runs into Tooru, who informs her about the real truth behind Masamune's actions and the true history of Toy Gun Gun.
On knowing the truth from Yukimura concerning the previous Toy Gun Gun members, Hotaru's resilience leads her to challenge Masamune to a duel, on the condition that she'd join the Team if she won even once against him.
