Best bank to receive money from US to Japan

Hi,

I've been doing research but couldn't find a definite answer. I've been living in Japan for half a decade, my work is based in the US.

My salary is being remitted directly to my JP Post bank, however, when I do the calculations, it seems that I lose about 5% of my money compared to current forex exchange rates.

For example if 1 usd = 158, JP Bank only gives me around 150 per USD.

I've read somewhere that Sony Bank or Shinsei has the best rates, but what's the best bank to use for regularly receiving money from the US? The amount monthly is about +-8000 USD.

does anyone have the same setup where you receive money regularly from the US? It would be really helpful if you can share the most cost effective way you're doing it.