on the 3rd December kazuha gave you his sweater and he said it looked better on you than him. You started to fall for him but... His eyes was locked onto someone else

she walks by and kazuha says to you "what a sight for sore eyes, brighter than the blue sky! "as he said that your heart ached

now today his sweater was on her and not you... You watch them from afar holding hands and enjoying themselves. She was getting warmer as you get colder..