I know kangmoo and kirin's relationship is toxic. Kangmoo a psychopath who don't have a feeling and emphaty but care for kirin. And kirin obviously love kangmoo but never say it because of kangmoo psychological condition. He even said he can't support kangmoo but he'll never left him. Toxic right? Yeah this story just closed to reality, much better than a 'fictional psychopath'where is most of the characters just bunch of idiot. But suprisingly, i like their relationship, like kirin said he is a tamer who live with the beast.
More suprisingly, i put this on my fav list
The Beast Must Die