This study aims at investigating the effect of the English language course design which is conducted on the basis of the approach called English for Specific Purposes (ESP). This English language course is designed based on the Universal Design for Learning (UDL) framework, which is increasingly drawing the attention of researchers and educators as an effective solution for diverse education settings in Japan. The UDL framework is considered as an efficient approach for designing flexible learning environments and accessible content. This ESP course design is based on the UDL guidelines and such design can match a wide mix of learner needs, abilities, background knowledge, and cultural differences. This research is part of a joint research project “A case study of inclusive class development based on UDL concept: Improving the first-year seminar and mandatory language subjects at Ritsumeikan Asia Pacific University (APU),” and is supported by the APU Center for Inclusive Leadership.