 But after a month-long negotiation between him and the Fighters, Ohtani announced that he would sign with the Fighters and spend some years in Japan before a possible MLB move.He was assigned the jersey number 11, previously worn by Yu Darvish.Ohtani made his debut at age 18 in the Hokkaido Nippon-Ham Fighters' season-opening game on March 29, 2013, playing as a right fielder.