Read both volumes in Japanese. The first half of volume 1 is sort of recap / intro to the world? From the second half, the main story picks up and over the volume and a half eventually arrives to an end. I don't know why these two volumes weren't included in the original 15 vol run. It seems that the original magazine it was published in got cancelled so they had to move it?? Anyway, with the original 15 volumes + these 2 volumes we get the complete story, which I'm happy for (vol 15 ended in a sort of cliffhanger / open ending). Recommended read if you want to know the ending of the story.

i love this, the at get more better and Haruka getting more more handsome~ The bl subtext is more strong in this one too