I'm Giving the Disgraced Noble Lady I Rescued a Crash Course in Naughtiness S01 E05 Naughty Hot Spring Trip

As a gift from townspeople, Allen and Charlotte visit Yunoha Resort. But it turns out to be a lovers' retreat, arranged by Eruca and Miacha. Soaking in a hot spring in swimsuits, sleeping in the same room... Their relationship rapidly develops.