While I don’t think there was a need to dedicate 8 volumes (albeit doujinshi-sized) just to the characters having animal ears, I understand that some of the fanbase will desire exactly that and nothing more, and I can respect the author for delivering the content. However, this is still overally a work of subpar quality. The art is even worse than the main manga. It’s low effort sketch-like style. Like come on, this being a doujinshi is no excuse for that. And it actually keeps getting works throughout the volumes. Some of those panels are barely legible. Or barely even panels. The content is heavily fanservicy withthe characters licking over each other within first few pages, so it’s no wonder rape, infamous staple of Koisuru Boukun, didn’t take long to happen.
“You’ve raped me”
“Sorry uwu ;-;”
Truly a pinnacle of BL storytelling. Remember kids, if you force yourself on someone, just say sorry and they will fall in love with you because they’ll realize your feelings. You might possibly object with “Don’t kinkshame, some people just enjoy fictional rape”. Sure, as long as you admit this is just porn and has no narrative merit whatsoever.

Yes, storyline-wise this is even more ridiculous than the parent work. The author seems to forget this is taking in alternative universe where the main story didn’t actually happen and those are technically different characters, so a “heartfelt” declaration of love after what is an equivalent of one night stand is simple laughtable. There’s an attempt at slightly more serious (relatively) story in later volumes, which made it a bit less painfull to read, but at this point the series was still beyond saving.

That said, fans of the of the franchise will likely enjoy it and it’s unlikely anyone else will even think of reading this.