As the strongest vocalist in the sadly-defunct Melon Kinenbi, I think you could have done without the crap autotune effects on your debut solo single, 「killing my caddy」. And maybe made it sound a bit less like something cut from the soundtrack of Project Gotham Racing.
And maybe released it through something other than a Japan-only, cellphone-only streaming site. Look into selling on iTunes; any distribution mechanism that requires more effort than “Google for a torrent or a Hotfiles link” will never put money in your pocket. You have ten years worth of loyal fans who will click a simple “buy now” button, and you didn’t give them one.
It’s catchy, at least, even if it doesn’t sound much like you.