Matsumoto was born in
Takamatsu, Kagawa on 29 April 1993. A natural right hander, his father Yasuki trained him to throw with his left hand from two years of age. When growing up his ideal person was
Gorō Shigeno, the main character from the baseball-themed comic
Major; He was the school baseball team's ace pitcher in his final year, leading the school to victory in the Kagawa Prefecture tournament and earning a berth in the 2011
national high school championships. In the first round match against Okinawa Prefecture's
Itoman High School, Matsumoto threw 11 strikeouts in his team's 4–1 victory. Matsumoto's powerful performance, along with being the tallest player in the tournament at 193 cm, earned him the nickname "Eimei's
Randy Johnson". ==Professional career==