Complex sentence: The National Institute of Japanese Literature ("Kokubungaku kenkyû shiryôkan", 国文学研究資料館, or NIJL) was established in May of 1972 with the primary aim to preserve manuscripts and books relating to the study of Japanese literature.
Split into simpler sentences: The National Institute of Japanese Literature ("Kokubungaku kenkyû shiryôkan", 国文学研究資料館, or NIJL) was established in May of 1972. Its primary purpose is to preserve manuscripts and books relating to the study of Japanese literature.