Abstract: According to one embodiment, a CPU generates, based on a tone-marked pinyin search character string containing a wildcard “?” and acquired from a communication terminal, a tone-number-added pinyin search character string for wildcard search in which “0” is added to a character having no tone number (i.e., an alphabetical letter representing a consonant) and a tone number wildcard “?” is added to a position immediately after the existing wildcard “?”. The CPU also generates a tone-number-added pinyin entry word character string for wildcard search, by adding “0” to a character having no tone number in a tone-number-added pinyin entry word character string corresponding to a Chinese-Japanese dictionary entry word that matches a tone-number-omitted pinyin search character string. The CPU then compares the tone-number-added pinyin search character string for wildcard search with the tone-number-added pinyin entry word character string for wildcard search to determine if they match each other.