|see § List of discovered minor planets|
Koishikawa has been a staff member of the Sendai Astronomical Observatory since 1972. His research is based out of the Sendai's Ayashi station. The main-belt asteroid 6097 Koishikawa, discovered by Kin Endate and Kazuro Watanabe at Kitami in 1991, was named in his honor.
List of discovered minor planets
|3994 Ayashi||2 December 1988||list|
|4292 Aoba||4 November 1989||list|
|4407 Taihaku||13 October 1988||list|
|4539 Miyagino||8 November 1988||list|
|4871 Riverside||24 November 1989||list|
|5128 Wakabayashi||30 March 1989||list|
|5751 Zao||5 January 1992||list|
|6089 Izumi||5 January 1989||list|
|6190 Rennes||8 October 1989||list|
|6349 Acapulco||8 February 1995||list|
|6859 Datemasamune||13 February 1991||list|
|7485 Changchun||4 December 1994||list|
|7816 Hanoi||18 December 1987||list|
|8084 Dallas||6 February 1989||list|
|10500 Nishi-koen||3 April 1987||list|
|11514 Tsunenaga||13 February 1991||list|
|12252 Gwangju||8 November 1988||list|
|14032 Mego||4 December 1994||list|
|30963 Mount Banzan||29 November 1994||list|
- "Minor Planet Discoverers (by number)". Minor Planet Center. 4 September 2016. Retrieved 11 March 2017.
- Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (6097) Koishikawa. Springer Berlin Heidelberg. p. 509. ISBN 978-3-540-00238-3. Retrieved 11 March 2017.