Running water is not thought of as having a fixed rate of flow. Sometimes the water comes out strong, sometimes weak. Such is the “fluid” nature of the income levels for certain businesses. Mizu shoobai includes a variety of entertainment businesses-tea houses, entertainment spots, bars, massage parlors, and houses of prostitution. According to another etymological source, these businesses were situated along riverbanks, and thus the “water business.”
A: Mori-san no musukosan ne, kekkon shitai rashii kedo goryooshin ga hantai shiteru te uwasa nee.
B: Soo na no yo. Nanishiro, aite ga mizu shoobai no de rashii no yo.
A: Mrs. Mori’s son. It appears he wants to get married, but both parents are against it.
B: That’s right. I hear that the bride-to-be is from the entertainment business.