A geophysical observation dataset (borehole tilt, broadband seismic, infrasound, and GNSS displacement) accompanying the 2018 phreatic eruption at the Motoshirane cone of the Kusatsu-Shirane volcano. The data was obtained by the local geophysical observation network operated by Kusatsu-Shirane Volcano Observatory, Tokyo Institute of Technology. All time is JST (UTC+9). Terada et al. (2021), Yamada et al. (2021), and Yamada et al. (submitted) describe station locations and instrumentations. Tilt (text files: 20190123_stn_1_Hz.txt) format: yy/mm/dd hour:min sec NS tilt EW tilt Broadband seismic and infrasound waveforms (sac files) (ex: 1801230950_stn_cmp.s) *stn: station name *cmp: component GNSS displacement (pos file) (ex: stn1030_0591.pos) *stn: station name Displacements are calculated by kinematic analysis using 960591 (a GNSS station operated by Geospatial Information Authority of Japan) as a base station. The kinematic analysis was performed on RTKLIB (ver. 2.4.2, Takasu, 2013). See the header for each file for detail. References Terada, A., Kanda, W., Ogawa, Y., Yamada, T., Yamamoto, M., Ohkura, T., et al. (2021). The 2018 phreatic eruption at Mt . Motoshirane of Kusatsu – Shirane volcano, Japan: Eruption and intrusion of hydrothermal fluid observed by a borehole tiltmeter network. Earth, Planets and Space, 73. https://doi.org/10.1186/s40623-021-01475-4 Takasu, T. (2013), RTKLIB: An Open Source Program Package for GNSS Positioning. Yamada, T., Kurokawa, A. K., Terada, A., Kanda, W., Ueda, H., Aoyama, H., et al. (2021). Locating hydrothermal fluid injection of the 2018 phreatic eruption at Kusatsu-Shirane volcano with volcanic tremor amplitude. Earth, Planets and Space, 73(1), 1–15. https://doi.org/10.1186/s40623-020-01349-1