  A Korean-Japanese planet search program has been carried out using the 1.8m
telescope at Bohyunsan Optical Astronomy Observatory (BOAO) in Korea, and the
1.88m telescope at Okayama Astrophysical Observatory (OAO) in Japan to search
for planets around intermediate-mass giant stars. The program aims to show the
properties of planetary systems around such stars by precise Doppler survey of
about 190 G or K type giants together with collaborative surveys of the
East-Asian Planet Search Network. So far, we detected two substellar companions
around massive intermediate-mass giants in the Korean-Japanese planet search
program. One is a brown dwarf-mass companion with 37.6 $M_{\mathrm{J}}$
orbiting a giant HD 119445 with 3.9 $M_{\odot}$, which is the most massive
brown dwarf companion among those found around intermediate-mass giants. The
other is a planetary companion with 1.8 $M_{\mathrm{J}}$ orbiting a giant star
with 2.4 $M_{\odot}$, which is the lowest-mass planetary companion among those
detected around giant stars with $>$ 1.9 $M_{\odot}$. Plotting these systems on
companion mass vs. stellar mass diagram, there seem to exist two unpopulated
regions of substellar companions around giants with 1.5--3 $M_{\odot}$ and
planetary companions orbiting giants with 2.4--4 $M_{\odot}$. The existence of
these possible unpopulated regions supports a current characteristic view that
more massive substellar companions tend to exist around more massive stars.
