The translator made this comment about the last chapter:
"This chapter is the second longest in the entire series I think"
As for the anime:
http://www.animenewsnetwork.com/anim...r/haganai_next
"Although Yozora Mikazuki faced a certain incident at the end of summer, the daily life of the Neighbor's Club goes on as usual. A strange nun, members of the student council and other new faces make an appearance, causing Kodaka Hasegawa's life to grow even busier.
While they all enjoy going to the amusement park, playing games, celebrating birthdays, and challenging the “school festival”—a symbol of the school life normal people live—the relations amongst the members slowly begins to change…"
At animenewsnetwork they mention 12 episodes.