I've possibly made a big observation regarding the cat & bunny pictured in this post.
I think that Hiruko's lavender scent might've come from Takumi himself around who knows how many loops ago, because one of her favorite gifts is the bath floral scent mysteriously purple colored. He must've gifted her it and it stuck with her ever since, It'd make sense, right? Her obsession with Takumi must've come from somewhere atleast and it'd be a nice detail.