The Pretense of Spring - S1.E15

"When all are sheltering within, there comes an imitation of spring. Linger in bliss for too long and your flesh will soon be frozen..."

Caught in a blizzard, Ginko is decides to look for shelter and finds a home where the owner, Suzu allows him to stay the night. The next day Ginko sees a boy, Miharu who seems to be fascinated by Mushi. Ginko learns that Miharu once disappeared into the mountains in the winter and then suddenly came back in spring, able to see Mushi. Miharu has been repeating this since and it may be caused by a "Harumagari" so in the end, Ginko decides to teach him more about Mushi.