Red String: Cupid's Love

Love. They say love is unconditional. It makes people feel happy, fulfill and complete. But it also makes people feel sad, pain, and miserable. People say that it was the work of Cupid that makes us fall deeply in love for someone; when he strikes his arrows of love to his targets. It is his duty, isn't it? Do we know the reason why he's doing this? Is he happy seeing a couple fall in love on each other? Cupid, as we all know is the god of love/desire but we don't know why he is entitled the god of love.