
Why can’t they be normal siblings? Do they have to declare undying love in a vague way each and every time? This manga has given everything but a normal sibling relationship

They have this thing called blood bond. Once a vampire bit another vampire, they'll create a link between them. The bond gets stronger once they consume each other's. Ai already drank Ren's blood and vice versa. They will be craving for each other as nothing can break the link. Except if their memories got erased.
Zero mentioned before that he felt depraved when he was separated from Yuki. Yuki also drank from him so the bond was created between them. That's what the bond does when he didn't drink from her.
While Zero also drank from Kaname before but the latter didn't bite him so the bond was only halved on Zero's part. Or so I believe lol
Zero didn't suffer from Kaname because he has Yuki to survive. This is what I thought. I might be wrong though

I too have no outstanding qualities or skills and feel incompetent to even try applying for a job. Anyway, is there no online school or something he can do so that at least he has a high school diploma? And then he can deal with the struggle of having no significant college degree like me who went for the arts and not the charts
To your boyfriend in the middle of an exam??? It’s not a romantic movie where everything works out with no problems. Sunwoo is trying too much to be a saviour at the cost of his own well-being. That job rejection consolation could’ve waited after the exam like tf.