Kiss because it's a woman's MV. What's the story?

Once, two people met and fell in love. Once, the girl accidentally blinded her eyes. The boy gave up his favorite racing car and gave his cornea to the woman! Later, when she left, the girl was very sad and another boy took advantage. Later, the girl found him but didn't recognize him. Only a dog accompanies the hero, telling us that love is far from loyalty to a dog!