The Okayama Planet Search Program (OPSP) was started in 2001 with the goal of spectroscopically searching for planetary systems around stars. It reported on the detection of 3 new extrasolar planets: (18 Delphini b, xi Aql b, and 41 Lyncis b), around intermediate-mass G and K giants 18 Delphini, Xi Aquilae, and HD 81688. Also, it updated the orbital parameters of HD 104985 b, the first planet discovered around the G giants from the survey, by using the data collected during the past six years. Since 2001, it has been conducting a precise Doppler survey of about 300 G and K giants using a 1.88m telescope, the High Dispersion Echelle Spectrograph (HIDES), and an iodine absorption cell I2 cell at the Okayama Astrophysical Observatory (OAO).
| Arion | 10.3 | 2008 | |
| Fortitudo | 2.8 | 2008 | |
| Arkas | 2.7 | 2008 | |
| 81 Ceti b | 5.3 | 2008 | |
| Spe | 4.8 | 2008 | |
| 6 Lyncis b | 2.01 | 2008 |