Episode 1: I'm Used To It

The episode opens three years in the past, where warships ring a small island but hold their fire, since ordinary weapons mean nothing against the monsters within. The Jeju raiding squad takes the fight on foot, but the lower-ranked hunters buckle under waves of red ants until a hooded figure drops in, healing the wounded while his two companions clear the field. They are an S-Rank trio: Baek Yoonho, who dispatches a giant white ant with ease, plus Eunseok and Min Byung-Gyu. From a nearby city, Choi Jong-In rains fire on advancing ants and orders his Hunters Guild forward.

A decade earlier, gates to another dimension tore open worldwide, spilling out magic beasts while granting some humans the power to fight back. These hunters are graded from E at the bottom up to S, their strength fixed forever at the moment they awaken. At a construction site, the famously feeble Sung Jinwoo arrives to join a raid; far from disliked, his presence signals an easy job, and his colleagues greet him kindly. He chats briefly with healer Lee Joohee, who frets over his old injuries, then checks the cheap, low-power dagger that is all he can afford before stepping last through the portal. Meanwhile, Association chairman Go Gunhee tells his aide Woo Jinchul how essence stones harvested from beasts fuel both the economy and government research into clean energy.

Inside, Jinwoo's joy at finding his first essence stone is cut short by a goblin that wounds him before teammate Park Gi-Sool finishes it and Joohee heals him. The party fells a werewolf boss and loots, and then Kang Jeongho discovers a hidden double dungeon. With the team deadlocked, the deciding vote falls to Jinwoo, the sole earner for a family with a missing father, a hospitalized mother, and a sister in college; he needs the money and votes to descend. Elsewhere, Cha Hae-In snatches a stolen purse from thieves and flees the crowd's attention. After a forty-minute trek, the party reaches a massive door and pushes inside.

The world of Solo Leveling is established, including the origin of gates, magic beasts, and the E-through-S ranking system whose powers never grow. The third Jeju Island battle is shown for the first time, and a roster of major figures debuts, among them the S-Ranks Baek Yoonho and Choi Jong-In, the swordswoman Cha Hae-In, healer Lee Joohee, team leader Chiyul Song, chairman Go, and Jinwoo himself. Jinwoo is framed as the weakest hunter alive, a man whose presence marks an easy raid. The episode closes by setting the events of the Cartenon Temple in motion, the double dungeon that will upend Jinwoo's life.

Inside the temple chamber, blue flames ignite as the team puzzles over ancient statues and inscriptions instead of beasts or loot. Joohee swears the largest statue is watching them. The door slams shut, and when a panicked member tries to force it, a guardian statue cuts him down before returning to its post. Recognizing the lethal pattern from his many near-deaths, Jinwoo screams for everyone to duck as the great statue's eyes fire a destructive beam that incinerates several hunters. He saves Joohee, then realizes the full scale of the trap they are in.

The episode adapts the first four webtoon chapters and was directed by Shunsuke Nakashige with a script by Noboru Kimura for A-1 Pictures, airing in Japan on January 6th, 2024. The opening theme is LEveL by SawanoHiroyuki[nZk] and Tomorrow X Together.

The adaptation reworks several beats. The raid party numbers thirteen here against seventeen in the webtoon, and Song Chi-Yul nominates himself as leader rather than asking permission, while voting cautiously rather than opportunistically. The introductory Jeju sequence and the early S-Rank cameos are drawn forward from the web novel, appearing far later in the manhwa. Go Gunhee and Woo Jinchul's exposition on the Association and essence stones as clean energy is added, as is Jinwoo carrying a dagger rather than entering unarmed, his goblin fight, the werewolf boss kill, and the Cha Hae-In purse rescue. Cut from the anime are Jinwoo's frustrating search for coffee before the raid and Song Chi-Yul lobbing a fireball down the tunnel to gauge its length.