He wanted her. There were no other words for it.
For as long as he could remember, she was there. Taunting him, flaunting herself in front of him. He wanted her, and she knew it. She knew it, and she took advantage of it.
Of course, she didn't want him. Who would? He was a freak, in body and in mind. He knew this, and had long since abandoned all hope of ever having someone who truly cared about him as an individual.
But still, he wanted her. And without hope of love, his wanting of her developed into something far darker. Lust. Hatred. Wrath.
She always kept out of reach. She knew what he was, and what he wanted to do to her. She didn't care. She didn't care that she had caused this in him, or that he only grew more evil with each instance of her taunting.
She enjoyed tormenting him too much to stop.
And one day, she got too close to him.
He moved quickly, and he claimed his prize. She screamed, of course, but that didn't stop him. There was no one around to save her, no one to hear her screams. He rent her clothing asunder, and partook of her flesh in the most beastly manner possible.
She cried. This... thing... that she'd created had finally turned on her. And now, it had decided to turn the tables. It raped her, it bit her, it listened to her whimper and moan. Eventually, she stopped crying. There was no point to it. There was no hope.
And as the eyes of the Harvest Goddess glazed over with despair, the Kappa smiled. At last, her taunting would end. At last, her body would serve him.
His smile widened, and pure malevolence radiated from his face.
At long last, they were together.
At long last, she was his.