Carlos Alcaraz The defending champion returns to Tokyo as the top seed, but fitness will be a key talking point after his lengthy injury layoff. He has only recently returned to competitive action, so his early matches will be closely watched.
Arthur Fils
The 2024 champion comes into Tokyo in excellent form and remains one of the most interesting names in the field. However, he starts in qualifying after missing the main-draw entry deadline.
Rafael Jódar
Jódar has enjoyed a sensational breakthrough season and has been remarkably consistent, rising into the top 20. The young Spaniard also arrives with strong momentum after an impressive Laver Cup performance.
Taylor Fritz
Fritz brings plenty of experience in Tokyo, having won the title in 2022 and finished runner-up to Alcaraz in 2025. His current form is a slight concern, but his record at this venue makes him one to watch.