Frustrated Japan coach Jamie Joseph on Wednesday made a flurry of changes to his starting XV for this weekend's Asia Rugby Championship match against South Korea.

Joseph, who blasted his side for lacking heart and effort following last week's 47-29 win in South Korea, introduced eight into his first team including World Cup winger Akihito Yamada for Saturday's clash at Prince Chichibu Memorial Rugby Ground in Tokyo.

The New Zealander selected Atsushi Sakate as hooker alongside tighthead prop Genki Sudo and Shintaro Ishihara, who kept his place in the front row.

Joseph dumped his second row for Kotaro Yatabe and Samuela Anise, while Shuhei Matsuhashi steps in at No. 8 flanked by Malgene Ilaua and Naoki Ozawa.

Yutaka Nagare and Jumpei Ogura remained in the key scrumhalf and No. 10 positions, respectively.

Yamada replaced Amanaki Lotoahea on the left wing with Lotoahea switching to the right. Rikiya Matsuda will man inside center instead of Ryoto Nakamura, who heads to the bench as one of Joseph's three reserve backs; Ryohei Yamanaka stays at outside center.

Ryuji Noguchi moved from the right wing to fullback, unseating Seiya Ozaki who was left out of the squad altogether.

Rounding out the 23 are Kaito Shigeno and uncapped Takuya Yamasawa as the backs. Takeshi Hino, Shogo Miura, Yu Chinen, Naohiro Kotaki and Yoshitaka Tokunaga are the bench forwards.