Mizutani is asteroid #8947 and also known as 1997 CH₂₆. Mizutani was discovered by the Japanese amateur astronomer Kobayashi Takao (小林 隆男) at the Ooizumi Observatory. Mizutani’s orbit is characterized by a semi-major axis of 2.76 Astronomical Units, an eccentricity of 0.21, a period of revolution of 1 673 days, and an inclination of 8.8 degrees.

Mizutani is named after a Hitoshi Mizutani, who shall be a professor at the Institute of Space and Astronautical Science, researches the internal structure of planets, played a leading role in Japanese lunar and planetary exploration, and be born in 1944 A.D. The Institute of Space and Astronautical Science has got a website also in English, but denies there to have a member of this name. Exclusively the Japanese part of the Wikipedia knows a Mizutani Hitoshi (水谷 仁), whose short description resembles very much the person in question here. But already the birth year is different and given as 1942 A.D. So whether or not this person is meant has to remain unclear.

At least Mizutani (水谷) must be the family-name in question because this is the only family-name, that I found with this pronunciation. Because the asteroid is named Mizutani, so actually nothing else than the family-name Mizutani (水谷) is needed for an interpretation. This name has one possible translation and this is water-valley. So Mizutani is of the water theme. Mizuno and other asteroids of the water theme and also asteroids named after valleys should be taken in account and compared with Mizutani wherever this asteroid seems to be relevant in an astrological chart.