The best word in sports is upset, and Koshien produces them like nowhere else. At the 2026 summer tournament, a school almost nobody outside Japan had heard of — Mie — walked onto the biggest stage in Japanese baseball and knocked out one of the tournament’s anointed favorites. If you want to understand why a whole country holds its breath every August, start here.
The favorite: Riseisha
Before the tournament began, Japanese analysts gave their top “S” rating — reserved for genuine title contenders — to just four schools. Riseisha, a powerhouse from Osaka with a long record of producing professional players, was one of them. They were supposed to go deep. Teams like Riseisha are the dynasties we’ve written about elsewhere: they arrive expecting to win, and usually do.
Here’s Riseisha earlier in the tournament, showing exactly the kind of quality that made them a favorite — a diving catch in center to bail out their pitcher:
This is Riseisha — the S-ranked favorite Mie would eliminate — in an earlier game (vs Kyoei), not the upset itself. It shows the caliber of the team Mie beat. Video: バーチャル高校野球公式チャンネル (Virtual Koshien, official) via YouTube.
The giant-killing
Mie didn’t just squeak by. They beat Riseisha 5–2 — a clear, controlled win over a team ranked far above them. The engine of the upset was their No. 10 left-hander, Ueda, who came in and threw five scoreless innings without issuing a single walk, quietly strangling one of the tournament’s most dangerous lineups. With the win, Mie reached its first quarterfinal in 12 years.
A No. 10 pitcher — not even the marquee ace number — shutting down a title favorite for five innings without a walk. That’s the kind of detail that turns a result into a legend.
Here’s Ueda doing exactly that — pitching out of a bases-loaded jam without giving up a run:
Mie's left-hander Ueda escapes a bases-loaded threat scoreless (shown here in another 2026 game, vs Matsusho Gakuen). Video: バーチャル高校野球公式チャンネル (official) via YouTube.
Why this one matters: the favorites are falling
The Mie result wasn’t isolated. Of those four pre-tournament “S”-rated favorites, two were already gone by this stage: Kanto Daiichi lost its opening game, and now Riseisha had fallen to Mie. Suddenly the bracket cracked wide open, and the teams left standing — Yokohama, Sendai Ikuei, and the survivors chasing them — inherited a very different tournament.
That is the beauty of single-elimination baseball played by teenagers. Seeding and reputation buy you nothing once the first pitch is thrown. A school like Mie, with one hot left-hander and nothing to lose, can end a favorite’s summer in an afternoon — and for the seniors on Riseisha, end their high school careers entirely.
Next up for Mie: a quarterfinal against Tenri. Win or lose, they’ve already done the thing that makes Koshien immortal — they wrote themselves into the story.
More: meet Yokohama, a genuine dynasty · the anatomy of a Koshien super-play · why the losing team cries and takes the dirt.