Episode 1

Secret Society of the Magic-Sealed City (魔封街結社, Mafū-gai Kessha) is the first episode of the Kekkai Sensen anime.

Synopsis
Leonardo Watch, an aspiring reporter, moves to Hellsalem's Lot, a city created by the intersection of the "Alterworld" and where New York City once stood, and through a series of lucky coincidences, is recruited into the secret society named "Libra."

Summary
Leonardo write a letter to his sister Michella wanting to tell her he is doing fine and wants to tell her how he changed and no longer feels worthless.

Six months earlier in Hellsalem's Lot, Leonardo is chasing a monkey that took his camera. As explosion occurs, Zapp Renfro appears and tells Leonardo that he didn't come to their meeting point and wonders if he really works for Libra. Few hours earlier, Leonardo is at Diannes Diner, where he speaks with Vivian and explains he is apprentice reporter. But as his stomach growls, her father and Vivian give him a burger, telling him he will wash the dishes later. A Sonic Speed Monkey then comes and steals his camera and he starts chasing it.

Zapp takes Leonardo with him and calls him Johnny. When they go to Libra, Klaus Von Reinherz welcomes him as Johnny Landis, but Chain Sumeragi says that can't be possible as Johnny just died. Leonardo apologizes for lying, but hearing about the secret organization Libra, there was something he though they may know. The King of Depravity, Femt, appears on TV being bored and unleashes a demon who is looking for his other half. He comments that a gate will open each few mins with the other half and it would be bad if the demon finds the gate first. In that moment, Klaus senses something and a gate opens next to Leonardo and cuts the building. Zapp thinks Leonardo is working for Femt, but Chain explains Klaus protected Leonardo and the gate came from the monkey. Chain then goes after the monkey. Klaus asks Leonardo if he saw the attack and if that's due to his eyes and Leonardo confirms. Leonardo explains that six months ago, he was with his sister and family at the Statue of Liberty and a strange entity appeared and asked them which one would see this through, making them realize the other one will loose sight. Zapp blames him for sacrificing her sister eyesight, but Leonardo crying explains he froze in fear and as he couldn't say anything, his sister told the entity to take it from her. HLPD then arrives and shoots at Klaus and the rest thinking they are responsible for the incident. Klaus believes Leonardo's eye would help them in this case and offers him to work for them and they will help him achieve his goal and once again welcomes him to Libra. As the HLPD troops surround them, Klaus tells Leonardo he isn't a coward as he still stands and is still looking for solution. Klaus then defeats the HLPD and tells them to go.

Zapp and Leonardo head looking for the monkey, and receive a call from Chain informing them that the monkey is heading their way and the gate will open any moment. As the monkey passes them, the gate opens and it cuts everything around them. Leonardo sees Vivian's diner was destroyed and promises to help her, but then the other half of the demon comes and Zapp protects Leonardo from its attack. Zapp tells Leonardo to take care of the monkey, before the gate opens again and then uses his ability and cuts the demon. As the demon regenerates, he keeps fighting him. Leonardo reaches the monkey, which was trapped from the debris. While looking at it, he sees the gate is a flea and not the monkey, so he kills the flea. Femt them rages as he though they would kill the monkey and that would have merged the two halfs of the demon.

Later, Klaus speaks with Steven who asks him if he wants to take in the boy which posses the "All-Seeing Eyes of the Gods", and Klaus confirms, stating they just need to handle the situation if something happens. Leonardo visits the still destroyed diner, ordering coffee and saying that he will do the dishes later.

Characters

 * Michella Watch
 * Black (Name wasn't revealed)
 * K.K. (Name wasn't revealed)
 * Zapp Renfro
 * Leonardo Watch
 * Steven A. Starphase (Name wasn't revealed)
 * Chain Sumeragi
 * Dog Hummer & Deldro Brody (Name wasn't revealed)
 * Zed O'Brien (Name wasn't revealed)
 * White (Name wasn't revealed)
 * Klaus Von Reinherz
 * Sonic
 * Vivian
 * Femt