Judo Joe is Joe Smith, an American high schooler raised in Japan, where he became a master of...judo. He confirms most of these assumptions right off the bat:
In addition to judo, it appears that Joe has learned a bit about zingers of the verbal variety...
Judo Joe looks to be the only comic published by Jay-Jay Corporation (I'm assuming the company name is connected to the character). The three issues of his adventures can be found here (as always, I can't guarantee you won't hit upon some good ol' historical racial insensitivity, but at least this comic is from the "forward-thinking" 50s). Something kind of cool is that the character is all about empowering others by teaching them judo, and the comic itself featured some simple judo lessons:
You can also check out Judo Joe on the PDSH wiki here.
Real name: Joseph Smith
5 Hero Dice
Devastating judo move (melee) +8 (2D damage)