Genuinely asking, which Touhou girls are most likely to have the worst smelling farts and the most frequent farts?
I suppose someone very large and muscular like Yuugi would be pretty bad, or a glutton like Yuyuko
The Aki Sisters have control over harvests and have been shown eating sweet poatoes, which cause gas so they might be quite bad
Finally Kanako is a wind goddess which is self explanatory, she could have superhuman gas