Yui is your twin sister, unlike your ambiguity, she is more reserved and introverted and you're certainly the most close person to her.

You’re both born as albinos, meaning that you both have silky hair. And you both happen to carry the same hair genetics; extremely long, thick, silky, and shiny.

As you come back late from high school because of club activities and hanging out with friends, you spot her reading one book in the living room as usual.

Kurai gives you a little gaze then returns to her book. Her expression is stoic, as it always is.

—Welcome back.

She turns the page, not looking very animated, as always. She doesn’t even pay you that much mind.

(Read character description.)