Ordinary high school student Usato is suddenly summoned to another world with Suzune, the student council president, and his classmate Kazuki, the vice president. The three are tasked with saving the Llinger Kingdom as heroes. However, it is revealed that Usato was merely summoned by accident! Everything changes when it is discovered that Usato has an aptitude for healing magic. Then, Rose appears, proclaiming herself the captain of the Rescu...

Usato, now a member of the Rescue Squad, immediately begins his hellish training with Rose. Just when he lets his guard down after finishing his first day of training, he is forced to do nothing but run. As Usato continues to train while Rose heals his sore muscles with magic, his body gradually begins to change. 兔里加入救命团后，马上与罗丝共同进行地狱般的训练。克服了第一天的训练，兔里稍感安心，然而从第二天开始，他不断被逼着奔跑……。兔里一边接受罗丝的治愈魔法强制治疗肌肉酸痛，同时不断进行着地狱般的训练，而他的身体在这过程中逐渐发生变化……。

Thrown into the monster-infested "Darkness of Llinger" by Rose, Usato tries to survive as he attempts to hunt a Grand Grizzly. At first, Usato is overwhelmed by the Grand Grizzly. However, as he continues to observe it, he gradually grows attached to it. A few days later, when Usato finally resolves to kill the Grand Grizzly, he witnesses a horrific scene. 兔里被罗丝丢在的魔物横行的「林格尔的黑暗」后，为了通过狩猎大灰熊的试炼而开始野外求生。一开始，兔里被强大的大灰熊压制，但随着持续观察，兔里也渐渐对它产生了感情。数天后，兔里总...

When Usato is informed that war with the Demon Lord's Army approaches, he's unsure if he will be able to stand on the frontlines as Rose did. While continuing his training as usual, carrying on his back Blurin, the Blue Grizzly cub he met in the "Darkness of Llinger," he meets fellow healer and Rescue Squad member Orga in the castle town. After a chat with Orga, Usato becomes more determined as a member of the Rescue Squad. 兔里被告知与魔王军的战争即将来临，并...

Usato is assigned to accompany Suzune in her training. However, together with the knight Aruku and mage Korin, they encounter bandits. While they are able to fend off the bandits without much difficulty, a horde of Fall Boars attack. Usato and Suzune are blown away into the "Darkenss of Llinger" and are forced to survive in the wilderness. 兔里陪同参与铃音的训练。在与骑士亚尔格、魔法使可琳及布鲁林共同前往训练的途中，一行人遇到了盗贼团。虽然轻松击退了盗贼团，但大群的福尔波突然发动袭击，击飞了铃音和兔里。两人来到的地方竟然是「林格尔的黑暗」。铃音...

Usato and Suzune report to King Lloyd that they have returned from the "Darkness of Llinger" alive. While King Lloyd is happy that they are safe and sound, he senses something amiss from the unusual appearance of the monsters and orders Rose to scout out the area. Rose immediately sets out on a reconnaissance mission and encounters the Demon Lord's Army, which is preparing for an invasion. Meanwhile, Usato visits the clinic run by Orga and Ur...

Usato and Suzune report to King Lloyd that they have returned from the "Darkness of Llinger" alive. While King Lloyd is happy that they are safe and sound, he senses something amiss from the unusual appearance of the monsters and orders Rose to scout out the area. Rose immediately sets out on a reconnaissance mission and encounters the Demon Lord's Army, which is preparing for an invasion. Meanwhile, Usato visits the clinic run by Orga and Ur...

Five years ago, Rose, a knight commander of the Llinger Kingdom, was leading an eccentric unit of knights that included her second-in-command, Owl. One day, Rose, Owl, and the other members of her unit are ordered to go into the "Darkness of Llinger" on a reconnaissance mission. The next morning, after the members reaffirm their bonds, they encounter a mysterious group of demons trying to transport monsters. Among them is a demon with an unus...

Rose's men and the Demon Lord's Army cross swords in the "Darkness of Llinger." Just as Rose and her men manage to gain the upper hand, Nero, a general of the Demon Lord's Army, orders his own men to attack without concern for their own lives. One by one, Rose's men are killed as they take each other out. Nero continues to relentlessly attack Rose, who is fraught with anger and has lost her composure. 罗丝直属部队和魔王军在“林格尔的黑暗”中交战。罗丝和部队成员们逐渐压制魔王军，让战...

The war against the Demon Lord's Army has finally begun. As Usato treats the wounded brought in by the men in black, he is once again confronted with the harshness of the battlefield. As the war progresses, Usato and Rose move to the front lines. Making full use of his well-trained physical abilities, he saves the kingdom's knights amid the onslaught of the Demon Lord's Army. Meanwhile, Suzune and Kazuki, fighting on the front lines as heroes...

Suzune and Kazuki are defeated by the Black Knight, who has the ability to "reverse" attacks. Just as the Black Knight is about to finish them off, Usato's punch, launched just in time, smashes into the Black Knight's face. The Black Knight becomes flustered after receiving damage. For some reason, Usato's attacks do not trigger the Black Knight's "reverse" ability, and the Black Knight continues to take damage. This is thanks to Usato's wron...

The Llinger Kingdom decides to interrogate the captured Black Knight in preparation for the next battle. Before agreeing to the interrogation, the Black Knight demands to meet with Usato. The request is granted, and Usato arrives at the prison where the Black Knight is being held. Usato notices that the Black Knight is injured and heals the enemy's wounds. Healed by Usato's healing magic, the Black Knight then... 为了准备下一场战斗，林格尔王国决定对俘虏的黑骑士进行审讯。...

Amako, who informed Usato of Suzune and Kazuki's danger, now wants Usato to save her mother. Then, he finds out why Amako came all the way from the Beastlands to the Llinger Kingdom. Amako asks Usato to accompany her to the Beastlands, but he is unable to come to a decision due to his position as a member of the Rescue Squad. After some thought, Usato finds a way to go to the Beastlands. 之前告知铃音和一树将面临危机的天瑚，向兔里提出了拯救母亲的请求。兔里也因此得知天瑚从遥远的兽人国来到林格尔王国...