Maki-san was the sadist seme who loves Ren deeply in his heart but the one who Ren loves wasn't him yet his brother. Maki-san was met completly imprinting was called Arata from extraction of Amamiya's data before a day of his birthday. Arata didn't know why why... he wanted to be with Maki-san badly even they just met or that was the memory from Ren? Their stories started from that day until the day that Maki-san said he wanted to cancel Arata imprinting to make sure Arata would like to stay with him after he has canceled it.
"The one Ren love wasn't me, but my brother. But my brother was straight and married so he used me, who looked like him, as a substitute. We were similar in not only our bodies but our voices as well... if he closed his eyes it must have felt like he was with my brother. I didn't know anything and treasured him, I did anything for him... and bought him everything he wanted because I believed Ren's heart was completely mine. So for 7 years before you came... I have kept it bottled up. Surprisingly, it was changed recently thinking that your feeling for me is the imprinting makes me undeniably lonely." sadist Maki-san said.
Void (zariya Ranmaru)