Hemipelagic sediments contained in 7 cc plastic cubes were analyzed for paleomagnetic and rock magnetic properties. Samples were collected from Hole C0023A drilled during International Ocean Discovery Program (IODP) Expedition 370, off Cape Muroto, Shikoku Island, Japan, which took place in 2016 (Heuer et al., 2017, https://doi.org/10.14379/iodp.proc.370.2017). A series of magnetic measurements were carried out at the Center for Advanced Marine Core Research, Kochi University, Japan. These analyses include magnetic susceptibility, natural remanent magnetization and its alternating field demagnetization, anhysteretic remanent magnetization, and isothermal remanent magnetization. Detailed rock magnetic measurements, which include hysteresis parameters, characterize magnetic mineral assemblages in terms of abundance, grain size, and composition. For further information on the methodology, please refer to “Read Me” document.