  We present Atacama Large Millimeter/submillimeter Array Band 3 data toward
five massive young stellar objects (MYSOs), and investigate relationships
between unsaturated carbon-chain species and saturated complex organic
molecules (COMs). An HC$_{5}$N ($J=35-34$) line has been detected from three
MYSOs, where nitrogen(N)-bearing COMs (CH$_{2}$CHCN and CH$_{3}$CH$_{2}$CN)
have been detected. The HC$_{5}$N spatial distributions show compact features
and match with a methanol (CH$_{3}$OH) line with an upper-state energy around
300 K, which should trace hot cores. The hot regions are more extended around
the MYSOs where N-bearing COMs and HC$_{5}$N have been detected compared to two
MYSOs without these molecular lines, while there are no clear differences in
the bolometric luminosity and temperature. We run chemical simulations of
hot-core models with a warm-up stage, and compare with the observational
results. The observed abundances of HC$_{5}$N and COMs show good agreements
with the model at the hot-core stage with temperatures above 160 K. These
results indicate that carbon-chain chemistry around the MYSOs cannot be
reproduced by warm carbon-chain chemistry, and a new type of carbon-chain
chemistry occurs in hot regions around MYSOs.
