It all started out as an obligatory medical service. To cure the magical knight Oscar Garland of his mana poisoning, the otherworlder Rin Tachibana must regularly service him sexually. But not only has she found herself starting to enjoy the thrill of having her colleague's pleasure at her fingertips, but Oscar has started to catch feelings for her, not knowing that she's the woman who's been anonymously pleasuring him at night! This initially pragmatic arrangement has gotten a whole lot more complicated. What'll happen when they finally embark on their work trip together?
