Tanaka led his high school team to a championship in the National High School Baseball tournament as a junior for Komazawa University Tomakomai High School in 2005 and a runner-up berth in the same tournament as a senior in 2006. Tanaka was the Eagles' first-round pick in the 2006 Nippon Professional Baseball high school draft and was the team's ace until the end of the 2013 season. From 2012 to 2013, he won 26 consecutive decisions, which broke an NPB record. Tanaka was repeatedly scouted by MLB representatives during the 2013 season and eventually signed with the New York Yankees, earning an All Star appearance in his first season.

This Rawlings official MLB baseball was signed in blue by Tanaka and includes a JSA sticker.