Woah, woah, WOAH, let's pump the brakes here for a second, buster. What do you mean main story concluded a while ago? They haven't fucked yet and still have regular conflict, miscommunication and cockblocking.
I loved the first part of DEAD Tube up to chapter 54. Personally, this manga ended at chapter 54 when . Each arc had a bit of mystery and a new thrill to it. The Rascal Arc being my personal favorite.
I've read now up to chapter 66 but it just keeps going into a loop of plans within plans...