The following conclusions:
There were some differences between hugging and hugging. Hugging was to use one's hands to gently close the distance between two people, not necessarily hugging each other, while hugging was to tightly hug each other. Hugging was more suitable for couples, but hugging had a wider range. It could be used between relatives or couples.
In addition, according to the usage in the Northeastern dialect, hug can also refer to hugging or hugging someone or something. In terms of emotional expression, Northeasterners were more inclined to use hugs to express their love and support for their relatives and friends.
To sum up, hugging was an action of gently closing the distance between lovers, while hugging was an action of hugging tightly together, which could be used between relatives or lovers.
Nezuko is initially 12 years old in the manga. As the story unfolds, her age doesn't change significantly in a traditional sense, but her character development is quite remarkable.
A simple Nezuko and Zenitsu fanfiction could be that they go on a journey together. Along the way, they encounter other demon slayers who are initially skeptical of Nezuko. But Zenitsu stands up for her, explaining that she's different. This shows the depth of their friendship and how Zenitsu has come to trust Nezuko completely.