If we're talking about a Japan Band version of UILforms or UIL's competition results page...Not one that's in English (At least none that I'm aware of but like you, if someone else knows of one I'm all over it). Some of the Japanese Americans from Kyoto Tachibana's fandom have helped source things a bit though from the All-Japan Band Assoc. website (honestly the whole page is a pretty interesting read). Check out the link and scroll about halfway down the page. Those results are for HS marching band. The national results for HS/MS/ES wind orchestra are on that AJBA site buuuut you'll have to do a bit of blind digging. Be sure to have Google Translate handy for the AJBA pages .
Anyway, here's a list of the handful of HS Wind Orchestra groups that have consistently won Gold (1st division) at Nationals for the past decade (only about 7-9 bands in each division receive Gold each year nationwide):
Seika Girls HS (came to Midwest in...2010?)
Saitama Sakae (came to Midwest in 2014 & 2006)
Tamana Girls HS
Osaka Toin HS
I don't have anything yet for MS and ES. I've only recently just started to dive into that realm.
Fun fact about the National Wind Orchestra competition. They don't use HS or College band directors as judges, they hire professional musicians from the Tokyo Symphony, Tokyo Kosei Wind Orchestra and other similar ensembles.