The authors developed “Science Learning Aids for Students in a Social sciences and Humanities (SLASH) track” for high school students who could hardly recognize the relevance of science. SLASH is a test-typed learning material consisting of video clips and questions that contextualizes how science relates to the following two situations: social sciences and humanities disciplines in university and civic life. This study aimed to evaluate the effectiveness of SLASH on changes in “belief in the relevance of science.” 208 high school juniors from two schools took part in the investigation. In a post-questionnaire, students reported their sex and initial interest in various topics and rated any changes in their “belief in the relevance of science.” The relationship between the change of their belief and their sex, initial interest, and SLASH answers were analyzed. The results showed that 1) the difficulty of SLASH would be balanced for high school juniors at mid-level high school, and easy for those at advanced-level high school, 2) SLASH could change their belief positively, and 3) SLASH’s positive effects were not restricted by participants’ sex, initial interest, and comprehension level. It is suggested that SLASH could have a positive impact on diverse students’ belief in the relevance of science.