The last one, the Mitsubishi B1M was designed by former Sopwith draughtsman (not Sopwith chief designer as he is often erroneously credited with) Herbert Smith, who went to work for Mitsubishi in 1921 as designer/engineer.
A lot of British aviation technical staff ended up teaching aircraft design in Japanese universities and companies post WW1 as there was no work for them in the UK.
A number of the design features on the A6M show that Jiro Hirokoshi was a student of one or more of those Brit expats.