I think Shimakaze's popularity as a trap option (I usually see this happening with boys cosplaying as her) is because of the absurdity of the idea that someone dressed in such scandalously skimpy but still obviously feminine clothes could actually be a male. At the very least, it should be extremely hard to hide a penis under the microskirt if it so much as gets half an erection, let alone if said microskirt gets blown off and trap!Shimakaze only has that extremely small thong on his lower body.
They basically want to see how they can top Hideyoshi Kinoshita in his trap-ness.
This is a question that has had me fucked up and I need answers. So animal tails are extensions of their spine right? So in doujin and such with girls with dog tails does that mean it's connected to their spine?!?! Idk man my brain hurts.