Seiji Rokkaku is a Japanese actor from Hyōgo Prefecture. He was born in Himeji and raised in Takasago. Rokkaku is the vocalist of Rokkaku Seiji Band. He dropped out of Gakushuin University. Rokkaku became famous in Japan for his role as Mamoru Yonezawa in Aibou Series. He landed the lead role in AIBOU Series: Yonezawa Mamoru no Jikenbo spin-off film of AIBOU series.