Imahira played in the 2016 Open Championship for his first major appearance. He had an opening round 68, but shot 80 in the second round and missed the cut. He qualified for the 2017 U.S. Open and the 2018 PGA Championship but missed the cut on both occasions. Imahira was 53rd in the world rankings at the end of 2018 and missed out on qualification for the 2019 Masters Tournament, for which the top-50 qualified automatically. However, he later received a special invitation for the event. At the 2020 U.S. Open he did make the cut, but finished last among the remaining players.