  We discuss the discovery prospects for kg-scale dark matter with a
Yukawa-like long-range interaction in Kamioka Gravitational Wave Detector
(KAGRA). We consider the interaction range to be in the order of kilometers,
thus the dark matter may interact with multiple KAGRA mirrors simultaneously.
The induced signal strain is in many cases dominated by frequencies below about
130 Hz. Due to the geometry of the detector there is some strong directional
sensitivity. It turns out that KAGRA would be able to constrain such kind of
dark matter within a few years of operation. With our set of assumptions we
expect that KAGRA could detect a few events per year for 10 kg dark matter,
with a Yukawa interaction with a range of 10 km and an effective coupling
constant around $10^6$.
