Hitoha Miyamizu (mother-in-law)
Futaba Miyamizu (wife; deceased)
Mitsuha Miyamizu (daughter)
Yotsuha Miyamizu (daughter)
Toshiki Miyamizu is a side character in the film. He is shown to be a very busy man and is also the estranged father of Mitsuha and Yotsuha Miyamizu. Following his wife's death, he rejected the Miyamizu shrine and its traditions to pursue a career in politics. He became the mayor of Itomori at some point, and appears to have held that title for a significant amount of time.
He was, under his daughter's suggestion, responsible for the evacuation of Itomori during the Comet Tiamat incident. As all residents survived, he was scrutinized by the media for some supposed "hidden agenda." It is unknown what happened to him at the end of the film, as no mention is made of him in the film past the Comet Tiamat incident.