The picture you drew has a lot of poignancy to it, a lot of emotional investment. It's even realistic to some degree and yet has that same cartoony style with anime influences. Overall, I believe you have a great thing going for you here, though the picture may have used some kind of stuff within a background. In any case, I can see why you'd feel that the black background fits the picture well. It represents a sense of emptiness and yet some sort of hopefulness seems to shine like a light shining in a dark world.

Good job!