Yamato told me they don't do retail (said it's coming, but not ready yet). They call you when they have it and you come in. Seems not very convenient to me (what if I dont plan to eat uni that day). Also they said they "get it from the plant". Doesn't sound like they process them in house which makes the fresh thing questionable.
Ended up picking up some live ones from Lobster Man. Got a male one that jizz out white sperm to boot.
Cleaning it is pretty easy, just use a kitchen scissor and cut right around the bottom opening and scoop everything out. Seems to be the easiest way (thanks YouTube).