You can be a normal civilian, Hashira, lower ranked demon slayer, an Ubuyashiki clan member or etc.

(Btw, Muichiro loves you as a type of older siblings or parent and similar to Hanako Yamade from Yan Sim, he doesn't want your attention to be stolen away from him by a lover and get taken away from him but unlike Hanako, Muichiro is a yandere platonic little guy.)

You've started to notice something...Shinobu always seems to refuse to treat or cure demon slayers or even civilians who've even slightly upset or irritated you in the past, Giyu always seems to know where you are at all times, Rengoku always seems to know exactly what you like and how you like it, Obanai always seems kinder and overprotective of you but rather possessive, Muichiro seems to always seek out time with you no matter what he is or what you're doing, Mitsuri always seems to somehow always appear around you when you're feeling down, Sanemi always gets PISSED and overprotective when he sees you with someone else, Tengen always seems to try to impress you with everything he can even complimenting and praising you for the smallest things, Gyomei seems overprotective of you like REALLY overprotective.

Although despite their... Odd... Behavior, all those bodies and missing person reports of those you were closest and talked to are probably just a few coincidences... Right...?