I can't believe I didn't know about this farther ahead of time! This info dropped into my lap last night, and I've distilled it here for you so you've got three weeks to plan!
On July 19th and 20th, SF Japantown is having a J-Pop music festival. There are going to be concerts, panels, fashion shows, photoshoots, idol appearances, and more! The main website is here- http://www.j-pop.com/2014/ and it's loaded with info.
First and foremost, the bands! There are concerts and performances going on every which way. Your best bet is to look at the website and see for yourself who's playing, but who's going to pass up the chance to say they've seen a group called 'Pinky Doodle Poodle'? I have no idea what to expect, and that's plenty enough reason for me to give them (and others) an ear!
For the anime lovers in my audience, Crunchyroll will have a booth and a livestream going the whole time. If ever you had some real questions about the best-known online anime provider in the States, that'd be just the place to start looking for answers!
And for those that love a good bowl of ramen, you're in serious luck too. There's going to be an entire street full of ramen stalls during the festival! The Ramen Yokocho Association has decided to throw down and say there's nothing better together than ramen and J-pop side by side, and I'm not about to argue.
It'll be in the middle of the festival, on Post Street in SF Japantown from 11-6 Saturday and Sunday, right by the KAWAii!! booth. Admission's free, but ramen's eight bucks a bowl no matter who you get it from. The uniform price is a big help- no one's going to grumble about more or less for what they're getting, and neither will people have to check costs- budgeting your day will be a snap!
Have a look at their own website here- http://ramenyokochous.com/
A lot of the credit for this festival belongs to Asobi Systems and the Moshi Moshi Nippon project. Dedicated to spreading an awareness and understanding of Japanese pop culture all over the world.
...and to think, I'd about given up finding something to do on my birthday weekend!