  Sample return from the near-Earth asteroid known as 25143 Itokawa was
conducted as part of the Hayabusa mission, with a large number of scientific
findings being derived from the returned samples. Following the Hayabusa
mission, Hayabusa2 was planned, targeting sample return from a primitive
asteroid. The primary target body of Hayabusa2 was asteroid 162173 Ryugu;
however, it was also necessary to gather physical information for backup target
selection. Therefore, we examined five asteroids spectroscopically, 43
asteroids spectrophotometrically, and 41 asteroids through periodic analysis.
Hence, the physical properties of 74 near-Earth asteroids were obtained, which
helped the Hayabusa2 backup target search and, also, furthered understanding of
the physical properties of individual asteroids and their origins.
