Hey Author here. I thought i would give you guys some clarifications about the fan fiction. 

I know some of you are curioous about Seulgi's identity. So to clarify, Seulgi is a human. However, she identifies as an animal (in the fic's case, a young wolf/ wolf pup.) 

Wikipedia's defination of the 'otherkin': Otherkin are a subculture who socially and spiritually identify as not entirely human. Some otherkin claim that their identity is genetic, while others believe their identity derives from reincarnation, trans-species dysphoria of the soul, ancestry, or metaphor.

Basically to summarise, some of them identify themselves to be animals but trapped in the human body. They are not to be confused with furries. 

Why Seulgi is like that?

I personally will not elaborate on the why she is like this or how she became like this. This fan fiction is meant to be the sweet fluffy relationship moments that Irene and Seulgi has. HOWEVER, if you like to know more about how and why the otherkin exist, i suggest you do that research online :) 

Am I over-exaggerating the animal instincts?

No, I would never want to offend a community. Though my experience with the otherkin is on