Waiting for a Letter / Christmas in Kagai / New Year’s Eve in Kagai

S1 E6: Aomori Prefecture. Kenta pays a visit to Kiyo's Grandma's and notices that she has received a letter in her mailbox. When Kenta realizes it is from Kiyo, he remembers how she and Sumire secretly exchanged notes in school. It was then that something about Kiyo's handwriting had started catching his attention.