>>132814345It's a thing in Japan that if the bride's family is wealthier or more prestigious, the husband will take the name to keep it passed on and such.
There's also stuff like adult adoption where if the family doesn't have an heir they'll "adopt" a male adult who'll take the surname.
Akio, in Utena, for example, took his fiancee's surname, since her family owned the academy.
Before the recent developments where certain wards in Tokyo would recognize same-sex couples, this was also a legal loophole exploited in that, for example, a lesbian woman would be adopted by her partner or her wife's parents and they would enjoy most of the rights afforded to married couples/family members.