Curious about the past WTTC trials, I looked them up and voila! Ishikawa, Ito, and Hirano have never won.
Ishikawa qualified for 2007(doubles debut) and '09(singles debut) by recommendation, '11 by beating 3 top 20 players, '13-15 by All-Japan Champion, '17-19 by World Ranking.
Ito qualified...