Similarity of trademarks is determined based on (1) the similarity of the designated goods and (2) the similarity of the trademarks, rather than likelihood of confusion, per se as in the US.

With respect to the similarity of the designated goods, the JPO determines similarity based on the similarity codes assigned to the goods description, as specified in the official guidelines.

As for the similarity of the trademark, there are three criteria, which are pronunciation, appearance and meaning. Especially, in terms of pronunciation and meaning, the uniqueness of the Japanese language should be taken into consideration.

As to marks written in foreign languages, various pronunciations may possibly be applied for according to the way Japanese people might pronounce them. It is possible that your trademark application could be rejected by prior marks having a pronunciation that is quite different from the original pronunciation. For example, the following marks are considered as similar in sound: HOUGH and HAWK, ABSON and AVISUN, KALVAR and Calobar, OLSSON and ORSO, Car boy and Cowboy.

Furthermore, as to the similarity in meaning, marks in foreign language are often rejected by marks in Japanese having corresponding meaning or those that cause a similar association to the person who sees the mark.

Therefore, a foreign applicant is advised to consult their Japanese associate for professional opinions about similarity of marks.