As the tag suggests, this is to be used ONLY when the protagonist is an abandoned child, meaning child who is thrown away at an early age, willingly or unwillingly. This should have some impact on the story, and it is preferable to use this tag if the protagonist being abandoned is known early on in the story. Please note that the child can only be the protagonist.
I fell in love. Her name was Shirasaki Yukino. I could only look at her from a distance. However one day I heard that she already had a boyfriend. Even if I love her, I can’t have her. The devil sent me an invitation. I can make her mine!