I don't often engage in fantasy booking, but I had an easy idea to fix Tensai before they rebooted him as Sweet T.
He wasn't getting over because he was a fat white man, cutting promos in Japanese. It didn't make a lick of sense to anyone.
So you have him come out and cut one in English. Have him talk about how during his time in the WWE, he received nothing but scorn and hatred. He was as strong and powerful as a freight train, but all you cared about was his back hair. So he left, and he goes to Japan, and he hones his skill. After dominating the competition, holding the IWGP Tag Titles for a combined total of 907 days, he returns to America. Does he receive a hero's welcome, returning to his homeland as a victorious warrior? Does he finally receive the respect he fought for and earned?
No. Just more scorn, and more ignorance.
"I was to return to this land as a Lord of Destruction, a harbinger of disaster. A monster. But it is you, WWE Universe, you have shown me who the real monster is. An angry mob who will never be satisfied, and is undeserving of my presence."
And then from there you keep the Japanese gimmick and name, but repackage him and Sakamoto as yakuza type crime lords. Bring Yoshi Tatsu in to the fold and deck him out with a yakuza look and attitude too, give him something to do. From there you have Tensai Corporation, a crime syndicate bent on taking the WWE's Title belts, and shuttling them away back to Japan where people will honor and respect them, as the WWE Universe has shown themselves undeserving.
Also, get rid of his finisher, that was the other half of his problem when he returned. It wasn't working. Give him some big splash type maneuver called the Tsunami or something along those lines. Something with big impact that was more convincing then that silly looking face crush nonsense.
I think it would've worked a lot better, because there would have been something to his character beyond "fat white guy, speaks Japanese", and you're building up poor Yoshi at the same time.