DJMAX RESPECT V

To unlock the V LINK Mission Pack you'll need to own both V EXTENSION and V EXTENSION II, then you'll need to Max Combo all songs from both DLC packs at least once. You can do them on any button mode or difficulty so this shouldn't be too difficult just using 4B, then once you've done them all go into the Mission menu and the achievement should pop when you open the list of V LINK missions.