Motomiya's elder brother is Ryuji Harada, which is also an actor as well as a youtuber. His sister-in-law is Ai Harada, which is a TV personality and blogger. His nephew is the youtuber Kazuto Hirai . His wife is
tarento Akiko Matsumoto.. Motomiya was scouted after his older brother entered the entertainment industry and debuted in 1994
Spur wa Yukue Fumei (
Nippon TV). Contrary to Harada's brother who often plays "good" characters, he often plays villain, suspicious, or to-be-killed characters. Motomiya's son is a big fan of the Heisei
Kamen Rider series. He appeared in
Kamen Rider Blade as an Isaka/Peacock Undead (name given to the monsters of the show) so that "my [his] son will be delighted". When Motomiya appeared on the programme, he declared that he harassed the cast, through actions such as hiding the shoes of the persons cast to be the Rider, and doing "hatred efforts". Alongside his acting career, he's also the president of the mixed martial arts team Motomiya Juku. He's also a close friend of
Hitoshi Ozawa, and acts as a member and captain of Ozawa's baseball team. Motomiya's special skills are
kendo, MMA fighting, boxing, and baseball. ==Filmography==