According to an aspect, a key-value store (KVS) system includes a data management unit that stores a data KVS storing a pair of a data KVS key including information on a storage location of application data to be an access target object and the application data; and a key KVS storing a pair of an application key and the data KVS key. The data KVS includes a normal partition in which a size of a record for storing one pair is a predetermined specific size; and a special partition in which the size of the record for storing one pair is a size set according to a data size of the pair to be stored. A data relocation unit relocates a pair of a relocation target object to the special partition having the record size suitable for the data size of the pair.