User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-4911512-20150217171516/@comment-5119020-20150217171826

The 6 star quests require you to get to HR7 in the guild, as Rajang, Kushala Daora, Teostra, and Dah'Ren Mohran are required to fight before you unlock the first final village quest. Keep in mind that 6* was the last tier in MH4.