- Bats Left, Throws Left
- Height 6' 0", Weight 176 lb.
Ishii hit .189/.263/.260 for the Tokyo Orions as a rookie in 1965, starting regularly. He improved to .256/.302/.411 for a career year in 1966, with 10 homers in 316 AB. He made his lone Pacific League All-Star team. The Keio drop-out fell to .217/.270/.350 in 1967 and .193/.291/.307 in 1968, with his playing time reduced as a result.
Reiji had only 81 plate appearances in 63 games in 1969, hitting .230/.284/.405, then was just 4 for 23 with 3 walks and no homers in 1970. In the 1970 Japan Series, he was four for eight and cracked two pinch-hit home runs while driving in six. The Orions dropped the Series in five games to the Yomiuri Giants. Ishii won the Fighting Spirit Award as MVP of the losing team.
Ishii's Series stardom did not carry over into the regular season. He hit .210/.296/.258 in his usual bench role in 1971. Moving to the Hiroshima Carp, he was 6 for 39 with a walk, double and homer in 1972 and 4 for 20 with two doubles, a triple and a walk in 1973.
Overall, Ishii batted .215/.276/.331 in 1,326 plate appearances and 581 games in NPB. He later ran a golf shop.