[3] He then entered Nagasaki Nihon University Junior and Senior High School,[4] where he continued to play as a pitcher.

During the quarter-finals of the Nagasaki prefectural tournament in his junior year, he battled with soon-to-be Carp teammate Takeru Imamura of Nagasaki Prefectural Seiho High School, where he pitched a complete game, giving up only 4 hits and one run, and earned the win with a 3-1 score.

During the first round match with Hanamaki Higashi High School, however, despite having pitched 5 scoreless innings, he lost to pitcher Yusei Kikuchi (now with the Seibu Lions).

[2] After graduation, he chose to enter Kyushu Kyoritsu University instead of joining the 2009 draft,[6] wanting to be under the guidance of Coach Sei Nakazato who was responsible for rearing notable NPB pitchers such as Nagisa Arakaki and Takahiro Mahara.

Within four years, he was assigned to do pilates workouts, then moved on to full-fledged weight training, making him gain an additional 14 kg.

[6][7] In the Autumn 2010 Fukuoka Big 6 Baseball Tournament, he obtained a 5-0 win–loss record and a 0.63 ERA, which contributed greatly to his team's championship.

During the 2013 autumn draft, he was chosen as the first pick of three teams: Hiroshima Toyo Carp, Hanshin Tigers, and the Tokyo Yakult Swallows.

[11] On May 1, he pitched his first complete game against the Hanshin Tigers at Koshien, allowing only eight hits and two walks, while striking out seven, beating fellow rookie Suguru Iwazaki.

[13] He finished the season at 10-8 with a 4.05 ERA and 115 strikeouts in 26 appearances,[14] and became the first rookie in franchise history to win ten or more games in their first year since Toshikazu Sawazaki won twelve in 1997.