- Bats Left, Throws Left
- Height 6' 0", Weight 190 lb.
- High School Tokyo Gakukan Urayasu High School
- Debut April 6, 2002
- Final Game September 28, 2005
- Born September 9, 1973 in Chiba, Chiba, Japan
Kazuhisa Ishii made his reputation as a wildly inconsistent pitcher for the Yakult Swallows. His father encouraged him to play baseball as a way to develop his lungs as Kazuhisa had asthma from a young age. Ishii became a star in high school and was the first-round pick of the Swallows in the 1991 NPB draft. He spent most of the next year in ni-gun, making only 12 appearances for Yakult and having a 4.18 ERA and no decisions. In 1993, the 19-year-old went 3-1 with 66 K in 58 1/3 IP but had a 4.70 ERA. In the 7-game 1993 Japan Series, Ishii pitched one scoreless inning in game three and saw no other action as Yakult won the Series.
In 1994, Kazuhisa was 7-5 with a 4.08 ERA and walked 77 in 108 innings. He walked the most on the club and led with 54 appearances, 44 of them out of the bullpen. Ishii held his walk total at 77 in 1995 while increasing his innings to 153. He fanned 159 and allowed 112 hits in a fine 13-4, 2.76 year. His strikeout total was third behind Masaki Saito and Robinson Checo. Yakult won the Central League pennant and Ishii was third in wins behind Futoshi Yamabe and Terry Bross and second to Bross in ERA. He started game two of the 1995 Japan Series and allowed 2 runs in 4 2/3 IP before exiting.
In 1996, Kazuhisa was just 1-5 with a 5.23 ERA in 8 games and walked 22 in 31 innings. He had shoulder surgery that year. Yakult refused to allow Ishii to move out of the team dormitory when they said that the 23-year-old was "incapable of managing himself." When Ishii took a trip to Australia to spend New Year's with his fashion model girlfriend, Uno Kano, Yakult manager Katsuya Nomura became riled up and said that Ishii should have stayed home and let his shoulder heal.
Ishii returned to semi-regular action in 1997, going 10-4 with a 1.91 ERA and 120 strikeouts in 117 2/3 IP. He had the lowest ERA on the Swallows staff as they won the pennant, but Kazuya Tabata and Masato Yoshii both pitched more to arguably be the club's aces; Ishii did not qualify for the CL ERA lead or he would have clearly led the loop. On September 2, he threw a no-hitter. He won game one of the 1997 Japan Series in fine form, tying a Japan Series record with 12 strikeouts. He also won game five in relief to go 2-0 in the Series, with 15 K, no runs allowed and only four hits allowed in 11 innings. Atsuya Furuta beat him out for Series MVP honors.
In 1998, the 24-year-old southpaw went 14-6 with a 3.30 ERA. He whiffed 241 in 196 1/3 IP but walked 105. He led the Central League in both walks and strikeouts (87 more than runner-up Tomahito Itoh) and set a Nippon Pro Baseball record with 20 wild pitches. The wild pitch would be broken 9 years later by Nagisa Arakaki. He was 4th in wins and not among the top 10 in ERA. He amazingly had one walk-free complete game, the only one of his career.
The 1999 season marked further decline as Ishii went 8-6 with a 4.80 ERA though he fanned 162 in 133 IP. He got his first Opening Day start but led the CL in both walks (71) and wild pitches (9) while finishing second to Koji Uehara in strikeouts. Surprisingly, he made his lone All-Star team that year.
Ishii went 10-9 with a 2.61 ERA in 2000 with 210 K, 73 BB and 137 hits allowed in 183 innings. He struck out the first six batters he faced in the second of three straight Opening Day assignments. He became the second-fastest man in NPB history to reach 1,000 strikeouts. He edged Masahiro Yamamoto by mere percentage points for the ERA title, led the CL in strikeouts and wild pitches (11) but not in walks. In 2001, Kazuhisa went 12-6 with a 3.39 ERA, 82 walks and 173 strikeouts in 175 innings in a decline year. Shigeki Noguchi beat him for the strikeout title by 14, Shugo Fujii had two more victories and Ishii was 8th in ERA. Ishii started game one of the 2001 Japan Series and had a no-hitter entering the 7th. He struck out 12, walked five and allowed one hit in the victory to go to 3-0 in the Japan Series. Ryu Kawabata finished the game so he avoided his second Series shutout. It was the first one-hitter in Series history; six years later, Daisuke Yamai and Hitoki Iwase would combine on the first no-hitter, a perfect game. Ishii was part of his fourth Series-winning club. By the end of the year, his 80 wild pitches were the Central League career record.
After the year, the Swallows made Ishii available under the posting system. Los Angeles Dodgers pitching coach Jim Colborn called him "a scaled-down version of Randy Johnson." Shawn Green, who had played against him while on an All-Star barnstorming tour of Japan, said of Ishii, "He shut us down, a team full of guys like Bonds and Delgado. Everyone was really impressed with him. He was the most impressive pitcher we saw there for sure." With those glowing recommendations, the Dodgers outbid the Angels, Mariners, Mets, and Rangers by plunking down $11.3 million just for negotiating rights. The praise was much too high given his track record - he had never been named to the Best Nine, won a Sawamura Award or MVP and had been an All-Star once. He had two great years but several mediocre and several bad years. While he was routinely among the strikeout leaders, his control was abysmal.
Ishii turned out to be effective but the second coming of Hideo Nomo he definitely was not, giving up plenty of hits and walks; though he frequently wriggled out of trouble, his poor control often came back to bite him. On September 8, 2002, Astros centerfielder Brian Hunter hit a line drive off Ishii's forehead in the fourth inning that caused the pitcher to be carted off the field. Ishii missed the rest of the season. Ishii began the year 10-1 and catcher Paul Lo Duca said he had the best stuff of any southpaw in the National League but Kazuhisa was 4-8 in the second half and finished at 14-10 with a 4.27 ERA. He led the 2002 NL in walks, no unusual feat for him, and he was 4th in Rookie of the Year voting. Colborn said the longer American schedule was to blame but it was a typically inconsistent time for Ishii.
He tended to get gassed easily; his career splits show a pitcher who became horribly unreliable after the All-Star break (3.90 ERA before, but an eye-popping 5.54 after). This was no surprise to his Yakult club, which often became frustrated with his inability to pitch beyond 100 pitches or hurl complete games regularly. Ishii was known for his poor conditioning habits, smoking three packs daily and consuming lots of soda, alcohol and junk food. Ishii was 9-7 with a 3.86 ERA for the 2003 Dodgers, posting an ERA above league-average though he was second in the 2003 NL in walks. In 2004, he slipped to 13-8, 4.71 and his strikeout rate fell drastically. Paul DePodesta traded him to the New York Mets on March 20, 2005 for catcher Jason Phillips.
Ishii pitched one year for the Mets, going 3-9 with a 5.14 ERA while battling injuries and was released. He was 2-2 with a 1.76 ERA in a brief stint with the Norfolk Tides. Overall, Kazuhisa was 39-34 with a 4.44 ERA (91 ERA+) in his four seasons in MLB.
Like Shingo Takatsu, Ishii returned to the Swallows in 2006 after ending his MLB career. He was is 11-7 with a 3.44 ERA and 170 K in 177 2/3 IP to push his career NPB record to 89-53; his ERA was 3.38 entering the year. He finished 7th in the CL in innings pitched, tied Masahiro Yamamoto for 8th in wins, led in walks (59), was 4th in strikeouts and just missed the top 10 in ERA.
In 2007, Kazuhisa fell to 9-10, 4.16 with 163 strikeouts in 166 2/3 IP. He was 10th in innings, tied for fifth in losses, tied two others for the most homers allowed (21), hit the most batters (13), tied Hayato Terahara for third in strikeouts, was 9th in walks (49), led in runs allowed (90), led in earned runs allowed (77) and finished 4th with eight wild pitches.
After 2007, Ishii signed a two-year, 800 million yen deal with the Seibu Lions.
He became manager of the Tohoku Rakuten Golden Eagles in 2021.