While in Lhasa, he was stirred by the activism in Nepal against the suppression of
Nepal Bhasa and imprisonment of writers by the
Rana regime. He thought of doing something for his mother tongue, and started writing a grammar of the language that would be useful to students. In 1949, he returned to Kathmandu where he completed the manuscript. The grammar, entitled
Subodh Nepal Bhasa Vyakaran, was published in 1952. In 1951,
Thaunkanhe, the first Nepal Bhasa monthly magazine to be published from Nepal, began publication with Sagar as the deputy editor. In a bid to promote publishing in Nepal Bhasa, Sagar formed a partnership with two like-minded former Tibetan traders,
Purna Kaji Tamrakar and Ratna Man Singh Tuladhar, and in 1952 established Nepal Press at his home at 11/122 Asan Tyouda Tol, Kathmandu. Their equipment consisted of second-hand Vicobold letterpress machines imported from
Kolkata. Sagar was also active in a number of associations. He was a member of Dharmodaya Sabha (Society for the Rise of the Teaching), a Buddhist organization founded in 1944 in
Sarnath,
India by exiled Nepalese monks and dedicated to promoting
Theravada Buddhism. In 1957, he was secretary of the Kathmandu chapter of the
Nepalese Chamber of Commerce, Lhasa when it hosted a reception to honour visiting Chinese Premier
Zhou Enlai. In 1960, Sagar set up Nepal Printing Press and continued his service to Nepal Bhasa. He compiled a dictionary of original words with meanings in Nepal Bhasa, Nepali and English, and in 1998, published it under the title
Nepal Bhasaya Maulik Sabdakosh. ==Honors==