1. An information processing device, comprising: a processor; a memory; a handwriting command interpretation unit configured to interpret handwritten data, input by a handwriting input unit, as a handwriting command; a search key identification unit configured to identify at least part of the handwritten data as a search key; and a search unit configured to, when the handwriting command interpretation unit interprets the handwritten data as including a plurality of handwriting search commands and the search key identification unit identifies a plurality of search keys in the handwritten data corresponding to respective input positions of the plurality of handwriting search commands, process the identified plurality of search keys in combination.