[4][5] At the age of seven, Takefusa Kubo started playing football for FC Persimmon, then moved to a local club based in his home city Kawasaki.

[6] In April 2010, he was selected as a member of FC Barcelona School team and participated in Sodexo European Rusas Cup held in Belgium.

In August 2011, Takefusa Kubo had been invited to join FC Barcelona's youth Academy, La Masia, after passing the trial.

He returned to Japan in March 2015 in search of playing time, signing with FC Tokyo’s junior youth team.

On 5 November, he made his formal debut for the reserve team in the J3 League as a halftime sub for match against AC Nagano Parceiro.

[10] From the start of the 2019 season, Kubo became a regular starter for FC Tokyo in both the J.League YBC Levain Cup and J.League scoring goals in both competitions.

He became the youngest Japanese player in the Top 4 European leagues history that has played in a match with a record of 18 years, 2 months, and 28 days.

[31][32] On 22 October 2023, Kubo was instrumental in leading Real Sociedad to a 1–0 win over Mallorca, earning the man-of-the-match title for his performance.

[39] On 1 November 2022, Kubo was named in the Japan squad for the 2022 FIFA World Cup,[40] where he started in the group stage victories over Germany[41] and Spain,[42] despite being subbed off early in both matches.