It was discovered on 15 February 1990, by Japanese astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory in Hokkaidō, Japan, and named after their colleague Tsuruhiko Kiuchi.
These photometric observations revealed, that Kiuchi is a synchronous binary asteroid with a minor-planet moon orbiting it every 20.90 hours based on mutual eclipsing and occultation events.
The satellite's diameter is about a third of that of Kiuchi, which translates into 1.3 kilometers (secondary-to-primary mean-diameter ratio of 0.33±0.02).
[7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.40 and calculates a diameter of 3.86 kilometers, using an absolute magnitude of 13.676 from Petr Pravec's revised WISE data.
[5] Kiuchi itself has a rotation period of 3.6196±0.0002 hours with a small brightness variation of 0.1 magnitude, indicating a nearly spheroidal shape (U=n.a.).