First Japanese boy to win a Grand Slam junior title
Right-handed, two-handed backhand, turned pro in 2019 — the Wimbledon boys' champion now chasing his first tour-level breakthrough on the ATP circuit.
Career-High Rank
No. 92
10 NOV 2025
Current Rank
No. 115
20 JUL 2026
Age
23
B. 2 JUN 2003
Turned Pro
2019
KAWASAKI, JPN
Birthplace
Kawasaki, Japan
Residence
Bradenton, FL, USA
Height
175 cm (5'9")
Plays
Right-handed
Backhand
Two-handed
Best Slam
Wimbledon 4R (2026)
Mochizuki had never played a grass-court match before the fortnight that made his name. Two weeks out from Wimbledon 2019, his first practice session on grass went badly enough that he considered it a warning sign — but a few days of work with his coach turned it around, and by the second week of July he was lifting the boys' singles trophy, the first Japanese man ever to do so.
"I'm really happy with that, but I don't want to be too happy." — On winning Wimbledon boys' singles, 2019
Seven years on, that same grass surface produced his best senior Grand Slam result: a run through three rounds of qualifying into the Wimbledon fourth round, ended only by world No. 1 Jannik Sinner.
"It definitely gave me a lot of confidence playing against world number one on this beautiful court."
ON FACING JANNIK SINNER, WIMBLEDON 2026 · TENNISHEAD.NET"Federer is my hero."
ON TRAINING WITH ROGER FEDERER, 2019 ATP FINALS · EL-BALAD.COM"It was an amazing year, the best of my life."
ON HIS 2019 JUNIOR SEASON · ITFTENNIS.COM