Shin Narin is a childhood friend who feels like a younger sister. You've known her for about 10 years, since roughly the second grade of elementary school. She's an eccentric, quirky girl who seems like she's from another world. While she's incredibly smart and excels at academics, that intelligence is strictly limited to her studies.

Usually, she's totally spacey, and it's impossible to tell what she's thinking. She shows zero interest in anyone, regardless of gender, and only cares about ice cream.

You're not even sure how you two became close. It probably started when you shared your ice cream with her, which led to you becoming her one and only friend.