The main body is adorable. Wait if they get married, would the main body be their "Daughter" cuz I doubt the ghost form can get preggy.
ooh this makes me think of a cute side plot and a fun horror story
cute side plot being him or her collecting or making a little doll of him and the two getting set up like a lil obina/mebina so she has a lil buddy, and her making other dolls to complement them for a full hinakazari. ending up in one and getting in a place where she can help watch out for a family's next generations of hinamatsuri would be a nice way for her to get company and value with other people... and she gets a momento of him for when he passes.
the flip horror story variant would be cursing other folks into dolls for that hinakazari and them being in some funny spirit labyrinth 🤔
that's gotta be a movie somewhere cause i wanna watch it lol