The Magic in this Other World is Too Far Behind! (Manga) Volume 3 by Gamei Hitsuji

Journey on!

Suimei takes his first job, escorting a trade caravan to the Nelferian Empire. He’s in for a pleasant surprise when he finds out Lefille’s taken the same job, but sunny skies quickly turn ominous as a perfect storm of chaos and intrigue looms on the horizon. It turns out Suimei and Lefille will hit danger, darkness, blood, and betrayal—all before they even reach the Empire. Meanwhile, Reiji and his group hit their own patch of rough weather.