- Bats Both, Throws Left
- Height 5' 9", Weight 191 lb.
- High School Chukyo Shogyo High School
Toshihiro Hayashi spent sixteen seasons in Nippon Pro Baseball.
Hayashi had a 0-2, 3.31 record as a rookie for the Nankai Hawks in 1963. He went 3-5 with a 2.87 ERA and .220 opponent average in 49 games (8 starts) in 1964. In the 1964 Japan Series, he gave up two runs in 1 2/3 IP as Nankai beat the Hanshin Tigers for their last Japan Series title.
Toshihiro made his only Pacific League All-Star team in 1965, going 17-3 with a 2.25 ERA and .197 opponent average for his best season. He finished fourth in the league in ERA. In the 1965 Japan Series, he was 1-0 with a 1.46 ERA, beating the Yomiuri Giants in game four for Nankai's lone win of the Series. He only pitched four games (2 R in 8 2/3 IP) in 1966 and gave up two runs in one inning in the 1966 Japan Series (won by the Giants).
Hayashi was 0-1 with a 5.79 ERA in six relief outings in 1967, 8-4 with a 3.65 ERA in 1968, 2-2 with a 5.30 ERA in 1969 and allowed three runs (two earned) in two innings in 1970 to end his pitching career. Overall, he had a 29-17, 3.14 record in 150 games.
Despite having hit only .195 during his pitching career, Hayashi was converted to first base. He hit .270/.299/.301 in 68 plate appearances in 1971 and was 6 for 20 with three walks in 1972 but batted only .152/.268/.239 in 57 plate appearances in 1973. He was 1 for 2 as a pinch-hitter in the 1973 Japan Series, backing up Clarence Jones at first base, as Nankai again fell to Yomiuri.
In 78 plate appearances in 1974, Hayashi put up a .284/.321/.446 line to win a semi-regular role in 1975, but he fell to .224/.278/.327 in 216 plate appearances. He was 4 for 42 with a walk in 1976, 9 for 40 with 3 walks and a double in 1977 and got into one game without batting in 1978. He had hit .219/.273/.310 for his career.