Namboku Line is the oldest subway line in Sapporo. This line cuts longitudinally from north to south in this city.
Hokkaido University (Hokudai) is near from stations on this line. Hokudai is so large that this university has the several nearest stations. Some Japanese language schools are also on this line. This Line has connections to JR Lines at Sapporo station. Nakajima Koen station on this line is next to Nakajima Park.
Thus, it can be said that living near Namboku Line is suitable for international students who want to focus on studying but go to the downtown and parks sometimes. I think that it is better for long-term international students to live there, especially.