A Full Stop For the Two of Us - S1.E11

Astarotte gets a red clover-shaped mark on her back, allegedly a sign that she is becoming an adult, and Judit tries to push Naoya into fulfilling his job description. As Judit later finds out it is not the same mark, but instead related to the leaves on the World Tree turning red, Naoya and Asuha start feeling weird. Ini theorises that the magical balance between worlds is destabilising and the World Tree is attempting to eliminate foreign objects from the Demon World, namely Naoya and Asuha. Soon, Naoya and Asuha become unable to hear the others and vice versa, and they also discover the entries in Asuha's diary are disappearing. With Astarotte potentially at risk from the World Tree as well, Naoya and Asuha decide they need to return to the Human World. The castle holds a farewell party, where Astarotte exchanges gifts with Asuha before asking Naoya on a date.