Speak honestly and reflect by yourself:
If you died before the person you love, would you want them to never love or be loved that way again by anyone?
Personally, that puts your own love in question, did you really love them or did you simply wanted to monopolize their feelings forever?
Amakata would be happy to know Ukai lived a happy life regardless of what he did or whom he spent it with
Hmm...let's put it like this. If the love of my life died and I was pursued by another— I'd simply reject them politely because I physically and emotionally cannot bear the thought of replacing them with someone else. No one can replace them. I simply couldn't find anyone more beautiful or lovable other than my love. And since I'm someone who values chastity, devotion and intimacy only between lovers— I have every right to want that devotion and love for myself. Monopolize their feelings? Shouldn't it be mine to begin with? I don't consider myself wrong for wanting a love that only belongs to two soul's. So, no... I wouldn't and physically couldn't stop them from falling in love or giving the same love to someone else after I'm gone. But if they did, they were never in love with me... at all. I'm not fond of of the thought of being replaceable or someone else being able to take my place so easily. I guess that makes me selfish right? Yeah. Devotion is a choice. Consider reflecting on yourself.
Have you ever heard the phrase "if you love them, let them go"? I think this manga encapsulates a lot of that.
Love isn't about devotion, after all, you can be 100% devoted to someone or something you don't love.
Love is about being willing to accept change, to know how to appreciate what is right in front of you. Just because you've loved someone until they died, doesn't mean you can never love again or that you need to feel the same way forever.
Just because it changed, doesn't mean it was never there to begin with, his love for Amakata is eternal and everlasting in those years they lived together and in the memories they shared.
Ukai will never stop loving Amakata, he loves him in a way he'll never love anybody else, that's what irreplaceable, because there will never be another Amakata. Ukai loves him in a way and loves his current boyfriend in another. He fell in love with Amakata in his teens, while he fell for his current lover in his thirties.
Are we the same person we were 15-20 years later? Or did we not change at all?
Certainly there are some things that remain the same, but no one will love teenage and early-twenties Ukai like Amakata did, and no one will love early-thirties Ukai like his current boyfriend is.
Personally, I think it would be much sadder if Ukai lived his remaining years alone and stuck with a feeling he isn't able to let go, even though he wants to be loved again.
11 years is a long time already, he was more loyal than most, in my opinion.
"He was irreplaceable." My man Amakata deserved a loyal lover.