The final goodbye, Koya admits to Ren that he loves him more than a close friend and he wanted to be with him. The coat was a request from Ren to handcraft for Koya's birthday. And unfortunately his last birthday...
Koya: Master...I have something to tell you...but I...uh don't want you to be upset.
Ren: Koya, what is it?
-Tears welled up in Koya's eyes-
Koya: It's so painful keeping it together, But...I...love you. I have loved you since I became a butler at this manor, I want to hold you and I think you're amazing...I sometimes just want to kiss you and...I want you to caress me and love me forever, but I know you don't see me in that way.
Ren: Koya...I...had no idea you felt that way..
-Koya looks down at his feet-
-Ren lifts his head-
Ren: You don't have to be embarrassed.
Koya: I also have to tell you that I um...
Koya: I am dying.
Ren: Koya?! what! When did you? Why did you keep this from me? -Ren has tears in his eyes- -He hugs him- Koya please don't...
Koya: I have to...go. I don't want to be a burden.
Ren: Koya this is selfish! please don't go.
Koya: I have one last request. Tell Miine and everyone that I love them all and give them this -he hands Ren a letter-
Ren: Koya how long have you got...?
Koya: Not long...
Ren: How long?! Please...
Koya: A few hours.
Ren: A FEW HOURS?! -Ren cries even more clutching him even more, Koya feels even more skinnier than before- You have lost weight and you were going on about me not eat for a few days- This coat barely fits you anymore.
Koya: Goodbye Ren
-Koya walks off into the sunset-