Why "mediocre"? Since it would take more than one visit to properly assess a place, why would anyone go BACK to a place they thought was only mediocre? Or is this a masochistic kind of thing?
If you want to go to KABUTO, be aware that Sachio san will be gone the end of this month, and perhaps after that, you could get your wish. Sometimes non-Japanese can make decent sushi, but maybe that would be a better subject matter, as I have so often been "ripped off" by Chinese or Korean folks who seem to be horning in on the expensive Japanese food option, without properly learning the trade, which takes seven years, should you learn in Tokyo. Can you imagine getting Jasmine rice at a Japanese restaurant? That's more than mediocre! Don't worry, the place (Torioshi) is in Paris....