Haganai volumes 10-11 read:

Previously all but the final chapter of volume 10 had been available so finishing book 10 was easy.  It was different from the manga, in the book he agreed to become Yukimura's boyfriend.  However, it's quickly made clear that this agreement is shallow and phony in volume 11.  He actually prefers spending time with Rika and likes Rika better.  They don't have sex or make any future plans together, and eventually they break up again, so going out with her really served no purpose except to make Yozora and Sena back down from any attempt to bag him themselves.

It's not a very satisfying conclusion to the story, but it is in line with Kodaka's character who prefers to avoid things than settle them sincerely.  In a more heartwarming section of volume 11, Kobato learns how to study hard in order to reach the same high school as Maria so they can be friends together there.  Also, the Neighbors Club as a whole does a good job making a movie, concert and cafe together.

It's implied that in college Kodaka will eventually get together with Sena, as he turned Yozora down definitively, Rika turned him down definitively, he turned down Yukimura definitively, and so all that's left is Sena.  Given that the story can't, due to censorship, make the obvious pairing of Kobato x Kodaka, Sena was the best choice so I'm happy to have my half a loaf.

Upon graduating everyone in the club becomes rich and famous, as expected of their high specs.  It's as good an ending as any, though thin in the details.  One thing I noted with a smile is that the lyrics of 'Be my Friend,' were recited in volume 11, the exact same decision I made in '100 Waifus,' which I wrote well before reading this volume 11, and also included the lyrics to 'Be my Friend' as the best summation of this entire series and the character relationships within it.  The fact that the author and I are in perfect mutual understanding of this point, to the point that we both made the same decision to include these lyrics and no other at any other time or for any other series, proves how well I can write from the standpoint of other peoples' series.

It actually reminds me of my prediction in '100 Waifus' that Ai would love Yaichi even without shogi and then the author of Ryuuou had Ai say that herself in volume 14 of Ryuuou -- a book I didn't read until well after I'd finished writing '100 Waifus.'  I understand these characters so well I may as well be the original author to all of their works.

Next up is Ryuuou volume 15, which I hope is better than Haganai's lackluster ending.  But I'm just glad to have closure one way or the other, good or bad.  I just wanted to know what happened and now I know.  Thank goodness I can close another chapter in my book of life.  It sure took long enough.  I first became aware of Haganai in 2011 when the anime's first season aired.  So it's been over a decade to see this through to the end.  It's like the Space Launch System all over again.