This is what happened between a carefree girl and her friends...
Blue represents happiness and worry-free.
She changed everything because of a boy. She learned to be silent because of him, and became sentimental because of him. She became unhappy because of him, and...
He, because she also changed herself, became happy and smiling, and learned her happiness and her worry-freeness.
They were originally good lovers, but a third party appeared. What will be the ending of the Blue Alliance...