I'm going with the assumption that "stripe" in this case is supposed to be like strip because otherwise the joke makes less sense but it could also be streak. Maybe I'm wrong and mistranslating it though, as always please correct me when I'm wrong...
Also I'm glad Nue learned how to show instead of tell. She clearly had a good literature instructor.
Well going by the Pixiv tag for すじ, it appears to be more about the "Stripe" formed by the Labia Majora...
And I googled Labia Majora, thinking it was related to a certain mask... Protip : don't google words you don't know. And don't think that "a picture is worth a hundred words, so I'll skip the text and google a picture directly".
*GLEAAAAAAAAM* Oh,Well, if it's Youmu...Stripping is surprisingly goodStripping is good...If it's like that then I'm number two in Gensokyo!Her Swordsmanship (standing strip) is really pretty~
Both "swordsmanship" and "standing strip" are pronounced "tachisuji"
