The title literally translates to Yin and Yang. But I think you could also say it's black and white or light and dark. The title probably reflects on how copying is obviously wrong and yet Konata still wants to copy. Oh well. All of us who have been thru school know these sorts of people and have various ways of dealing with them. One of them is to tell them to FO. Another would be to refuse in different ways. Or we could be like Kagamin and let her copy the homework anyway. *shrugs*