Sekai Saikyou no Kouei: Meikyuukoku no Shinjin Tansakusha

Corporate slave Arihito Atobe's death in a freak bus accident marks the beginning of his new life as a kind of adventurer called a Seeker. Reborn into a fantasy world, he settles into a previously unknown job class called "rearguard," capable of providing his (all-female) party with critical attack,