7:58 - Katsuobushi are dried bonito flakes. A general nickname for what they're called is "okaka." Old Lady Okaka eats them, so hence her name. The "old lady" comes from her old age (obviously).

18:36 - The city Shione mentions here is Setagaya, which is located in Tokyo (and Tokyo is roughly two hours away from Tana, so it's relatively close).