A memory system includes a plurality of memory dies configured to store data; and a controller coupled with the plurality of memory dies through a plurality of channels, wherein the controller decides whether to perform a pairing operation, by comparing the number of pieces of read data to be outputted to an external device, which are included in a first buffer, with an output count reference value, and wherein, in the case where the number of pieces of read data stored in the first buffer is greater than or equal to the output count reference value, the controller gathers other read requests and logical addresses corresponding thereto in a second buffer, and performs the pairing operation.