Café 100 is the Hilo institution credited with putting loco moco on the menu since 1946. The place is a drive-in counter operation — you order at the window, eat at outdoor tables — and the prices are absurdly low. The loco moco here is the original version: white rice, a hamburger patty, a fried egg, and brown gravy. The menu has expanded over the decades to include a full range of plate lunches and over a dozen variations on the loco moco, but the original is the one to order.
It's not fancy — it was never meant to be — but it's exactly what it says it is: a quick, filling, inexpensive plate lunch that sustained the plantation workers and still sustains Hilo locals today. Cash preferred. Open for breakfast and lunch, closed Sundays.