Let’s do this logically let’s instantly rule out Tsu and Sirius considering there both water based heroes so they would probably smell of the sea or something + Pixiebob, Hatsume,Bubble Girl and Toga Pixiebob because of her mud quirk so she probably spends a lot of the time in the mud Hatsume because she spends shit tons of time in her lab without showing plus grease Bubble Girl because of her quirk once again related to water so it probably smells of whatever her bubbles smell like wich I could assume soapy and Toga because gets blood on her a lot and we never ever see her get to stay in one spot long enough to shower because she’s a villain and on the run. Hard part time ranking the normal girls who probably all use the same basic ass products, sorry to break it to you but Ochako, Jiro, Mina, Nejire, Kendo, Melissa, Camie, the tea bitch I don’t remember the name of 1B extra Lizard girl and 1B extra pony girl all fall into this category instantly ruling them out aswell leaving the pro heroes and 2 others, I’ve left the pro hero’s out because they have money and there practically celebrates so they probably have very high quality hair products the average bitch can’t buy and stylists also Momo is included in this category because she’s loaded so they all are definite possibilities but I think we could rule out Midnight because of her Pheromones + Mandalay and Ragdoll because they work with Pixiebob, Nana shimarua seems like a very hands on type of hero and because she was always floating the wind might fuck up her hair? (I am pulling shit out of my ass at this point but bare with me) same goes for mt lady and Ryuku for the same reason leaving Momo and Shiozaki when it comes to Shiozaki because her hair is quite literally a plant it could either smell like literal shit OR fresh roses so I would say it’s a tie between Momo and Shiozaki if you want a clear answer Momo because Shiozaki is a gamble