The first issue in vol.5 is prequel written by Noelle Stevenson. It tells the story of how the 5 main characters and Bubbles the raccoon met when the camp started. It is still true to the character I've met and loved in first 4 volumes. This also explains why I gave these two 2 stars instead of just 1. 

Afterwards, without Noelle Stevenson on the team, the story hopelessly tried to make April the single main character instead of the no-single-main-character strategy used in previous volumes. This feels weird, like why is April more special than the others. What's worst is that the story became totally predicable, doctrine about "friendship-to-the-max" and not fun any more. By just skimming the pages, I can already tell the story without reading all the fruitless small talk tries to be funny.