For elementary learners of Japanese, one of the main difficulties in reading is to distinguish words written in kana. This paper reports on a survey of elementary level learners with two different levels of proficiency to investigate the effectiveness of Japanese graded readers with parts of speech color-coded to distinguish nouns, verbs, adjectives, and adverbs. Compared to those who read normal texts, the participants who used this form-focused text tended to obtain higher scores in the post-tests which tested word recognition, function word recognition, and the relationship between modifiers and modified words. In addition, based on the recording of reading activities, form-focused text readers tended to read faster than their counterparts.