This study focuses on Japanese ideophones and conducts a survey to examine whether the Japanese syllabary that constitute ideophones give impressions sensed as “weight” Japanese ideophones include phonomimes, which imitate sounds, phenomimes, which depict states, and psychomimes, which represent psychological states. In the survey, respondents evaluated the impression of “weight” for each syllable in the Japanese syllabary, in hiragana, and katakana, including voiced sounds (and muddled voiced sounds) and p-sounds, on a five-point scale. As a result, we concluded that the Japanese syllabary has the impression of weight, with the muddled voiced sounds being perceived as heavy, and the vowel sounds in the “a” line (a, i, u, e, o), the voiceless sounds in the “ka,” “sa,” “ta,” and “ha” lines, and the p-sounds: “pa” line being perceived as light. Furthermore, based on the results, we proposed a system to visually represent the impression of Japanese syllabary sounds in respect of perceived weight. In this system, heavy/right is converted to the thickness and color intensity of the letters. Specifically, it incorporates a visual representation where thicker and darker letters are perceived as heavier, and thinner and lighter letters are perceived as lighter (weight), providing a function to experience the weight of ideophones used in actual manga. This is intended to help non-Japanese speakers grab the impression of weight of Japanese ideophones and enjoy them in manga more deeply.