"He's coming to me" also has to do with a love story between a ghost and a human. Where the love seems imposible and they try to deny that it's even there, but ultimately fall for each other in the end dispite the circumstances.

In dark blue kiss there is conflict that starts up as they try to keep their relationship a secret. As well as jealousy that arises becuase of it, and this is similar to what happens in together with me. The story just really reals you in. There is also a similarity to a character "threat" having a romantic interest in one of the characters.