  Study of in-medium mass modification has attracted interest in terms of the
restoration of the spontaneously broken chiral symmetry, which is responsible
for the generation of hadron mass. Many experiments were performed to measure
in-medium property of hadrons but there is no consensus yet. J-PARC E16 has
been proposed to study in-medium property of vector mesons via dilepton decay
channel. The status of spectrometer R \& D is explained. Other related
experiments planned at J-PARC are also introduced.
