A memory system capable of being connected to a host, includes a non-volatile memory that includes a plurality of non-volatile memory dies, and a controller that is electrically connected to the non-volatile memory. The controller is configured to manage the plurality of non-volatile memory dies as a plurality of die sets, each die set including two or more of the non-volatile memory dies to which priorities are assigned respectively, select one die set from the plurality of die sets based on an identifier received from the host, and select, based on the assigned priorities, a non-volatile memory die from the selected die set as a writing destination die of write data received from the host.