Unusual relationship

"Narcissistic, my god I love it. The perfect sacrifice" - Hira
I know kiyoi also has mental health issues just like hira, but that doesn't defend all his action to hira. Hira also has the same characteristics as those creepy obsessive stalkers in kdrama. So both of them are mentally ill. Imagine the continuation of their relationship... toxic.
Only koyama and his brother are sane in this drama. Sorry to all fans of this drama, but I didn't enjoy the plot of this drama. I had stomachache while watching this drama, idk why.