元社畜のアリヒトが転生先で就いたのは、正体不明の職業『後衛』。だがそれは、攻撃＆防御支援、回復もこなせる万能の職業だった！ そんなアリヒトのもとには、転生前の美人上司(年下)、ミステリアスな亜人の傭兵少女、そしてワケありの高レベル美少女剣士と個性的な女性メンバーが次々と集いはじめる。さらに『後衛』には、相手の後ろにいるだけで自分への好感度を上昇させる能力があることが判明し―!? 最強の見守り系支援職の冒険譚、開幕！
Workaholic assistant Atobe Arihito fell asleep in his company’s bus that was traveling for a vacation. When he awoke he learned he had died due to the bus getting into an accident, and that he had reincarnated into a world of reincarnators – to the Labyrinth Country. To his surprise he was discovered by his slave driving manager, Igarashi Kyouka, who further explains their role in this world.
In Labyrinth Country, Reincarnators are expected to choose a job and form parties to fight against monsters in Labyrinths. “Valkyrie” Kyouka had expected Arihito to work with her once again, but he declines due to his knowledge of her demanding nature. As they depart she vows to make him regret not choosing her. And thus starts Arihito’s adventure as a “Rear Guard”.