千客万来 (senkyaku banrai): a flood of customers, a thousand guests coming ten thousand times, the wish a shop hangs at its door for a trade that never stops. The thousand and the ten thousand are not counted but piled up, the way the dictionaries put it: many, and more. The phrase is Japanese, made out of Chinese parts by people who painted signs; no Chinese text has the four characters together. Its two oldest witnesses share the year 1811 and do not know each other. Shikitei Sanba, the Edo comic writer who kept a cosmetics shop, gives a showman the patter
the letters written on the back of the lantern: a thousand guests, ten thousand comings, ten thousand years, and wrote the older reading
senkaku over it himself; the great senryū anthology of the same year makes the joke that only works on a phrase everyone has already seen painted:
a thousand guests, ten thousand comings; if they all came, that would be a problem. A comic book of 1821 calls writing it on the signboard lantern
the sign-painters' first school, and a novel of 1834 calls it the tea-house custom. In the Meiji era it left the door and became an ordinary word for a crowd that keeps coming, but the first modern dictionary, in 1889, kept the wish:
a phrase merchants write to wish their trade well. The register is humble and hopeful, a small shop's door, which is why a novelist of 1894 could call the lantern's thousand guests
a wish so far past the truth it hurts. Brushed for a new shop, the word goes back onto the door it was made for.
four-character idiom 千客万来 is composed of the
kanji 千 (read sen) meaning "thousand",
客 (read kyaku) meaning "customers",
万 (read ban) meaning "ten thousand" and
来 (read rai) meaning "visits". The term is used as a wish for "doing a roaring business" or for "a constant stream of customers".