I must say yes
I think Sadaharu Oh deserves to be in the Hall of Fame. The Hall of Fame is not exclusive to the Major Leagues. The Hall of Fame recognizes several prominent players from the Negro Leagues and leagues before the National and American League.
The Negro Leagues never had official records. I'm not positive, but I think the only stat of the Negro Leagues is league champions. I'm not even positive they have that. Two players I can think of right off the bat is Satchel Paige and Josh Gibson.
Satchel Paige was a great pitcher. He claims he has pitched in thousands of games. That fact could be disputed, but the fact he pitched 3 innings with only one hit against him at the age of 59 should be an auto-qualifier. He was also a showman, and his transcending of the Negro Leagues is enough Hall of Fame credentials. But no official stats, you could dispute whether or not he belongs. I believe he does.
Next up is Josh Gibson, catcher. Rumors are he hit over 900 home runs, and I'm not so sure about him over Satchel Paige. He wasn't quite as influencial or famous as Satchel, but I guess I have to give him due credit. It's passed on as a fact, so it's pretty obvious if he didn't hit 900, he sure as heck hit a lot.
So why not include Sadaharu Oh, who undesputedly hit those 868 or whatever home runs? Sure, Japanese baseball is different from the baseball in America, but if other leagues get in despite not being associated by the major legaues, than greats of the Japanese leagues definitely belong.
"Baseball is ninety percent mental, the other half is physical."- Yogi Berra