
From what I understand it's the same level of shounen-ai as 07 Ghost and Silver Diamond. Where they don't outright say it but it's pretty fucking obvious.
(⊙…⊙ ) SPOILERS (⊙…⊙ )
So in the end, Mano tells Cabell he wants to stay by his side forever. He says it's not a proposal but is hesitant about saying that bit. Cabell says it is a proposal. That being a vampire isn't a joke. They end up agreeing to wait until Mano gets a little older if my translation is correct.
It's a common 'out' for mangakas who want to write BL but reach a wider readership by not being limited to BL specific publishing options.
Disappointing to not have the outright confession, but at least they'll be together forever and there's like...no chance they're not going to be romantically involved let's be real.
Funny how this is actually not a BL (not even shounen-ai), just a shoujo (supposedly confirmed by the author themselves) but some of us have already been trapped here and have the need to keep following the story