1. There might've been an anime or Manga cul-de-sac, if any such characters actually existed in 1947. If the preposed sequel ever gets off the ground, maybe one or two might show up.
2. It's a strange phenomenon for some British singers to sing with American accents, but it's something that's cultivated over time. For the first 15 years of the Kinks' existence, Ray Davies was proud to be so unashamedly British. Then he hooked up with the Pretenders' Chrissy Hynde, and slowly "petrol" became "gas", "motorways" became "highways", "The Underground" became "subways", "Wimpy's" became "Golden Arches", and his Cockney dialect slowly took on a Noo Yawk drawl. It must rub off on you, but it doesn't happen overnight.