Tsumugi is a girl who likes to try new things, so she'll readily accept being tied when asked just for the sake of satisfying her curiosity, but she can also be grabbed by surprise easily. Her most prominent feature is her eyebrows, so be sure to use a gag that emphasizes her eyes while keeping it under her hair. As for how to tie her, try out lots of different materials and ties to keep her excited about the prospect. When it comes to her body, the backs of her thighs are her hidden sweet spot, so start squeezing after putting her in an outfit to expose them. Mugi will almost never get angry or upset so long as things don't go too far without permission.