I mean, you have to look at it for what it is. Our little bunny was under the influence of drugs so strong they made it impossible for him to move, even as he was in so much pain he would pass out. His fiancée wasn't helping him, and was leaving him to suffer in that pain every single time. Yushi wasn't doing it with any bad motives, or trying to attack him, he was simply trying to help him so he wouldn't be in so much pain anymore. And both the bunny and his fiancée knew that, once it had come to light.
Then again, Yushi could've told Ren, right? Like "Hey bro, the drug has bad side-effects, your bunny will be in pain" Cause it seemed to me that Ren wasn't resistant to his fiance, he would've understood.
It seemed to me like both the bunny and Yushi thought Ren knew about the effects of the drug, and was leaving him alone despite knowing he would be in pain. Which would be why Yushi seemed so surprised that he didn't, and felt so guilty.
yushi said it himself that he tried to search for ren but he can't find him anywhere so yeah that happened
I dunno why it was absolutely disregarded, but don't you think Yushi deserves more beating? He touched somebody else's wife, ya know