Ever since that day after school when Kobato was called out by a letter, his happy high school life began. The cultural festival where the two of us wandered all over the school. Christmas, when the night breeze was a bit chilly. Visiting a shrine together for the New Year. In truth, Kobato never actually thought the day would come when he’d experience something like "a petty argument sparked by jealousy over a small misunderstanding."

——And yet, whenever an opportunity arises, Kobato casts her aside to engage in mystery-solving... The 3rd volume in the series.