Ahh. I sort of came under the idea a long time ago that something like a time loop might be happening, because the YT upload of the end credits theme has the description "This story is not an end yet. Because only you are in the infinity loop." At first, I assumed that was the title of the song, in that way that directly translated Japanese OST song titles never make any sense (especially since one of the LP forums I found when I was looking for screenshots of particular moments always called it that when linking to it in the "music for this scene is:" note.)

However, digging a little further, it appears that's a quote from some other visual novel or game or something, and the person who uploaded the Hatoful end credit theme was making a smart-aleck reference to it when he put that in the video description, and the people on that forum were just confused.

WELL, THEN.

Edit: I have just confirmed that, yes, if you romance Shuu in the first term, it does have the scene where you totally sell Yuuya out to his heavily implied death several months before the term ends, and yes, the BBL path does just proceed as normal with him inexplicably there again like nothing ever happened anyway.