Higashide graduated from Saitama Prefectural Asaka High School.

[5][6] In January 2020, Shūkan Bunshun revealed that Higashide had been having an extramarital affair with actress Erika Karata since 2017, when Watanabe was pregnant with their third child.

[9] On August 1, 2020, Watanabe finalized her divorce with Higashide, promising that they will work together to take care of the children.

[10] On August 27, 2024, Higashide announced his second marriage on his official YouTube channel to a non-celebrity woman upon learning of her pregnancy.

[11] It was later revealed to be former actress Karin Matsumoto,[12][13] and that the two had met before on set prior to her retirement from the entertainment industry.