According to one embodiment, a storage device includes a nonvolatile memory and a control circuit. The nonvolatile memory includes a plurality of storage blocks, each including a shift register. The control circuit controls writing and reading of data to and from the nonvolatile memory. The control circuit is configured to: read target data from a first storage block of the plurality of storage blocks; and write the target data read from the first storage block to a second storage block of the plurality of storage blocks, the second storage block being different from the first storage block.