Some mods require having at least 10 to 50 friends and potentially recommendations from three students who are in clubs.
In the current debug builds (1980s Mode and 202X Mode), you can perform tasks for Student Council members, but you remain a "delinquent" in their eyes. They will still confiscate your weapons and follow you if you act suspiciously. This void is exactly what modders have filled. yandere simulator join student council mod new