In Japanese, the term yutosei, or “honors student,” has a wide range of usage that can go beyond the animate. For instance, in the food retail business, eggs and milk are often referred to as “excellent pupils” in that they’ve maintained a stable price over time.
Eggs in particular. Between 1955 and around 1980, the price of 10 eggs (about a kilogram) fluctuated between ¥200 and ¥350. By the bubble years of the late 80s the price had stablized back to around ¥200 and has essentially stayed there ever since, which means that it costs about the same to buy an egg now as it did to buy one in the lean years after the war, when an egg almost qualified as a luxury food item.
Consequently, eggs have always held a certain iconic position in the Japanese diet, and lately have been used by supermarkets and other food retailers as loss leaders or medama shohin, meaning merchandise that are advertised at ridiculously low prices in order to draw customers into a store where they will presumably buy other products. The Price, Ito Yokado’s chain of discount supermarkets, last week was advertising packages of 10 eggs for only ¥99, and I saw a piece on TV Tokyo’s Business New Satellite that mentioned a supermarket that was selling them for ¥88.