I live in Washington state, and I'd be more than willing to help you. Have it shipped to my address, and I'll forward it along to whatever address you'd prefer in Japan (or elsewhere).
Surely, help from an internet stranger sounds weird. However, it's basically my standard operating procedure these days. Hosting foreign overland travelers, storing vehicles for travelers, helping with paperwork and registration of vehicles, title transfers, etc. Bank documents, DMV paperwork, buying and shipping parts/documents/papers etc. I'm hosting two Australian overland travelers early next month, and three British travelers in the middle of next month. I just housed a German bicyclist for 6 nights only a couple weeks ago, that I met in line at the bank! Basically, I just thoroughly enjoy helping people.
What more trouble could a birth certificate/apostille be? If you'd like assistance, feel free to contact me.