- Bats Right, Throws Right
- Height 5' 11", Weight 171 lb.
- High School Tsukumi High School
Kawasaki was picked in the first round in 1988 by the Yakult Swallows. He made the big club as a rookie, going 4-4 with a save and a 3.94 ERA in 1989. He had a 12-13, 4.05 record in 1990. The teenager tied Kazuhisa Kawaguchi and Koji Nakata for the CL lead in losses, led in hits allowed (194) and tied Kawaguchi for the most homers given up (26). He also made his first CL All-Star team.
Kawasaki improved to 14-9, 2.91 with a save in 1991. He made his second All-Star team. He was 6th in the league in ERA, between Kawaguchi and Hiroki Nomura. He did not pitch in 1992 (presumably due to injury) then was 10-9 with a 3.48 ERA in 1993. In the 1993 Japan Series, he won a 1-0 game four duel against Takehiro Ishii of the Seibu Lions, then he topped Hisanobu Watanabe, 4-2, in game 7 to give Yakult the title. He had a 2-0, 1.20 record on the Series with only 9 hits in 15 innings and was named MVP of that Japan Series.
After his hot finish to 1993, the right-hander never got on track in 1994, going 6-9 with a 4.79 ERA and a CL-worst 10 wild pitches. Kawasaki was excellent in 7 games in 1995 (3-0, 1.82) but hurt his elbow. He had surgery and missed most of the year (though he did toss a gem in game four of the 1995 Japan Series, eight shutout innings in a duel against Shigetoshi Hasegawa before allowing one in the 9th and getting yanked in a no-decision), returning for five games (4 R in 9 1/3 IP) in 1996.
Kenjiro had a 7-5, 4.19 record in 1997. He continued his postseason unbeaten record with another game four Japan Series outing. Facing the Seibu Lions, he gave up one run in 5 1/3 before being relieved; he got the win and Yakult won the 1997 Japan Series.
KAwasaki had his big year in 1998, going 17-10 with a 3.04 ERA. He was 8th in ERA but led the CL in wins. He also led in complete games (9) and tied Masahiro Yamamoto, Kenshin Kawakami and Sung-min Cho for the most shutouts (3). He won the Sawamura Award as the best pitcher in Nippon Pro Baseball despite not even taking his league's Best Nine at the position - that went to Kazuhiro Sasaki, a reliever. He also made his third All-Star team, the first in seven years.
Kenjiro faded to 7-11, 3.85 with a .293 opponent average in 1999. He dropped only one spot in ERA, from 8th to 9th. Kawasaki had a 8-10, 3.55 record in 2000 and made his 4th CL All-Star squad. He dropped one more spot in ERA, down to 10th, right behind Nate Minchey.
A free agent, Kawasaki signed with the Chunichi Dragons. He hurt his shoulder in spring training 2001 and missed three years. A comeback attempt in 2004 was a wipeout (3 starts, 2 1/3 IP, 8 H, 3 BB, 9 R) and he retired.
Overall, Kawasaki was 88-81 with two saves and a 3.69 ERA in 237 games pitched.