People need to stop phrasing it as if he went out and kidnapped some child to fuck.

She sought him out herself when she was 14. She suggested they meet up after chatting for 2-3 months (from somewhere in August to somewhere in October).
She admitted on the stream that she was the one to suggest they meet up and she went to his house and had sex with him.
Afterwards she kept wanting to meet up and he blocked her (again this is what the girl herself says but he later confirmed happened).
Later met again online by happenstance on a different account under a different name when she was 15 and they talked online for two years and then met up again when she was 17 and had sex again.
He didn't know who she was for those two years and even when they had sex as she was using a different name and had different hair color.
She finally told him who she was when he broke up with her again a few days ago and went to korekore to leak the whole story.
And again, he went on stream and confirmed this and apologized to her on the stream.
Gaou said that if she filed a police report he'd turn himself in.
Korekore managed to talk her into filing a police report and telling her parents (which she hadn't apparently). (She posted a screenshot of the message she sent to her mom on korekore's stream as well...)