ohh no, this reminds me of a message exchange I had with someone today (shoutout to you for lowkey helping me find a friend?) I was thinking about him being half naked. If Aku knows that Jack is half naked...? Does he know his enemy is running around half naked. (Does Jack... Himself know? Maybe he gets the sensory ick for the inner layers of a kimono or smth)
like,, jack did grow up in japan. he was eight years old when aku attacked. an eight-year-old knows what underwear is. a three-year-old knows what underwear is.
my headcanon is it's some made-up ritualistic thing that only exists in his universe—purity and humility represented by a minimal covering of undyed unadorned fabric; as befitting his quest to destroy evil itself, he is armed not with a weapon made of natural steel but rather made of spiritual virtue, and he is armored not with a suit of iron but with a robe of RIGHTEOUSNESS. so until his quest is over he's got to wear this outfit, like, symbolically.
i have this headcanon because there's no other damn reason he'd be dressed like that.
my headcanon is also that aku thinks he looks like he's in his underwear















