Shunya Chidori is the father of Kaname Chidori and Ayame Chidori and Widower of Shizu Chidori. He is the Serving UN High Commissioner of the Environment. His job was the reason for Kaname moving to the US at the age of 9. He was not present at the death of his late wife 4 years before the series. This lead to the estrangement between himself and his elder daughter Kaname.
He lives and Works in New York, NY with Ayame.
Little is known of him. He studied at Waseda University, his position is unique to the FMP timeline and doesn't correspond to a existing post IRL. Mithril seems rather worried that their existence could become known to him. He is only seen once in as a vision of a alternate timeline shown to Kaname by Sophia.