OSAKA, Japan — In a direct challenge to Japan’s high school baseball establishment, Shizuoka’s Katsuyoshi Oishi, the coach who led Katsuragawa Nishi High to its first Koshien victory in 26 years, has publicly opposed shortening all official games to seven innings. Speaking at an opinion exchange meeting on June 6, Oishi framed the debate not as a logistical fix but as a threat to the soul of the sport.

“The discussion about seven innings versus nine innings isn’t the real issue,” Oishi told attendees, including Japan’s former U-18 national team coach Kenji Ogura and Nippon Ham Fighters’ chief baseball officer Hideki Kuriyama. “What matters is preserving the experience of playing in Koshien during the summer, with the same rules that have defined high school baseball for generations.”

“If we’re going to change the format, we should ask ourselves: What are we losing?”

How Did We Get Here?

The push for seven-inning games stems from a 2025 report by the JHSBF’s “High School Baseball Issues Study Committee,” which cited scheduling pressures as the primary concern. With summer Koshien drawing record crowds—last year’s tournament sold out all 54,000 seats across its 18 days—the league faces logistical hurdles in maintaining its grueling schedule.

Yet Oishi, whose team’s 2024 Koshien victory (a 1–0 win over Oita Konan) became a cultural moment in Japan, rejects the idea that shorter games are the answer. “The summer tournament isn’t just about winning and losing,” he said. “It’s about the atmosphere, the history, the way the game unfolds over nine innings under those lights. You can’t replicate that in 42 minutes.”

Source: Asahi Shimbun (May 29, 2026) – Transcript of opinion exchange meeting

Oishi’s Case Against Seven-Inning Games

Oishi’s opposition rests on three pillars:

1. The Koshien Experience: He argues that the summer tournament’s nine-inning format is inseparable from its identity. “Players talk about ‘the moment they stepped onto that field’ for decades,” he said. “Shortening innings would dilute that.”
2. Regional Flexibility: Instead of universal seven-inning games, Oishi proposes targeted solutions for regional qualifiers, such as staggered start times or adjusted schedules. “County-level tournaments could experiment with seven innings,” he noted, “but Koshien itself should remain unchanged.”
3. The Long Game: Tactically, Oishi believes nine innings allow for deeper strategic play. “In high school baseball, the game often turns in the late innings,” he explained. “Taking that away removes a key part of coaching.”

“If we’re forced to go to seven innings, then we should at least ensure that the summer tournament stays at nine. That’s the non-negotiable.”

What’s at Stake for Japan’s Baseball Culture?

The debate extends beyond rules. At its core, it reflects a clash between:

Oishi’s stance also carries weight because of his recent success. Katsuragawa Nishi’s 2024 victory—its first since 1998—revived interest in high school baseball, proving that nine-inning games can still captivate audiences. “People came for the drama, the late-inning comebacks,” Oishi said. “That’s what we’re risking if we rush to seven innings.”

What Happens Next?

The JHSBF is expected to release a formal response by July, with potential pilot programs for seven-inning games in regional qualifiers starting in spring 2027. Key questions remain:

• Will Koshien stay at nine innings? Oishi’s allies hope so, but league officials have not ruled out changes.
• How will regional tournaments adapt? Some prefectures may adopt seven-inning games sooner, creating a patchwork system.
• Will this affect college or pro baseball? Currently, no—but the debate could influence future discussions in Japan’s professional leagues.

Next Official Update: The JHSBF’s summer baseball rules committee is scheduled to meet on July 15, 2026, in Tokyo. A final decision on seven-inning games is expected by August 1, ahead of the 2027 season.

How Does This Compare to Other Countries?

Japan’s high school baseball is unique in its nine-inning tradition, but other nations have grappled with similar debates:

Japan’s case is unusual because its high school and professional leagues already align on the nine-inning format—a rarity in global baseball. “This isn’t just about rules,” Oishi said. “It’s about what makes Japanese baseball special.”

Common Questions About the Seven-Inning Debate

As the JHSBF weighs its options, Oishi’s voice resonates with a generation of coaches who see high school baseball as more than a sport—it’s a cultural institution. “We’re not just talking about innings,” he said. “We’re talking about the next 50 years of Koshien.”