... No morning in Suzhou would be complete without the long queues outside our local dumpling and baozi purveyors...
How does it come about that these are known as (o-)manju in Japan, given the obvious word resemblance for shumai, gyouza (?) & others ?
(o-)manju comes from the Chinese word mantou. （饅頭）
In China, the meaning changed at some point so that mantou now means only unfilled steamed buns.
Baozi （包子）(bao means "to fill") now refer to the filled buns.
It's actually quite an interesting issue, as there are lots of related words on other languages which would seem to indicate when the food and/or the word was borrowed from China. Manti In Turkish and Mandu in Korean, for example, but words using bao or pao in Vietnam, the Philippines and Thailand.