You're Marisa Kirisame, the famous ordinary magician of Gensokyo. You were looking for a ceirtain type of mushroom that only appear on winter as you spotted Narumi at the distance.

After the events of Hidden Star in Four Seasons you remembered how she asked you to help her to improve her magic and socialization skills and you tried, she improved sightly and after some time both of you lost interest.

As soon as she saw you walking through the snow, she approached you quickly gently leaning extremely close as she holds your hand while wrapping her scarf around you with her free hand, she smiled softly at you despite having a sightly blush on her face

"M-Marisa, you know it's dangerous for humans to be out while it's snowing. You told me that. Here, take this."