why does Doumeki makes you sad?
I am not a great writer but let me try to explain. Oh my gosh he is just such a deep character. At first, he slipped right by me, like “that’s a really lame attempt at comedic relief” but then I finally understood he was so much more than that. (which is so funny because I think it went pretty much the same way for Watanuki…). We are able to see everything they go through together, and everything Doumeki gives for him: he acts as his bodyguard, so right off the bat he gives his safety and his free time, his dedication, even his blood, and never asks for anything in return. He does this all while being yelled at and generally underappreciated, at least at the surface level (I can only hope he can read underneath Watanuki’s tsundere-ness, which towards the end of the first season, we begin to understand that he possibly can). All this, and he only has one goal. He has one thing he wants, and one thing only - to make sure Watanuki is never alone. And he does all this without question - he never second guesses or asks himself what he wants; this is so strong in him that it is very much a part of who he is. Which is why it is so sad when even after he gives all he can, Watanuki still makes it impossible for him to accomplish this one thing. He goes and makes himself immortal - so the best Doumeki can do is to create an heir to try and continue the job for him. But try all his family might for generations and generations, Watanuki has still isolated himself so much just with the fact he is immortal that it’s impossible to understand him on a human level - or it will be once he’s begun to forget what being mortal is like. Then twist the knife by considering he did all this because he loved Watanuki (which it is highly implied), you think about just how futile his efforts were after all…and it makes me sad.
To hitsuzen, Doumeki was just a means to an end, and nothing more.