Koryo High School Signed Baseball: Nakamura & Hiramoto – “99.夏”

This baseball bears signatures (or handwritten names) of Shōsei Nakamura and Ginjiro Hiramoto, former high school stars from Koryo High School who competed in the Summer Kōshien (High School Baseball Championship) in Japan.

 • Born June 6, 1999, in Hatsukaichi, Hiroshima, Japan. 
 • Currently plays as an outfielder/catcher for Hiroshima Toyo Carp in NPB. 

 • Rose to prominence during the High School Summer Championship (“Summer Koshien”), including a standout performance in 2017 where he broke or tied home run records in that tournament. 

Ginjiro Hiramoto
 • Teammate of Nakamura at Koryo High School, played in the same summer high school tournaments. 

 • Delivered key hits in High School Championship games (e.g. two-run single) during summer tournaments. 
baseballjapan.org

About the “99. 夏” Marking:
The ball includes the inscription “99. 夏” (which means 99 Summer).

Possible interpretations:• Reference to a summer tournament where these players featured • Could be associated with their year of birth (both born in 1999)• Or could be a tournament‐season notation (Summer 99) rather than specifically denoting age or birth year.

There is no confirmed evidence that “99.夏” here literally marks the exact match date or birth year at time of signing.

Why This Is Valuable

An authentic piece (or close to) from the high school era of two players who went on to play in NPB (for Nakamura) and made notable contributions as amateur stars.

Summer Kōshien memories are highly cherished in Japanese baseball culture — especially for collectors.

Even without full professional signatures, items from that era (high school tournament) with names of future stars tend to be rare and sought after.

⚠️ Please note: Display case is NOT included.
📦 Carefully packed to international shipping standards
📦 Ships within 1–2 business days after payment