Niino is a childhood friend of Jean and has been his friend at least since high school. Niino takes pictures for a journal and sometimes keeps Jean and his sister company since the siblings know him well.
Niino is the son of a man that is a subordinate to the royal family. At a very young age, Niino and his father abandoned their old lives to look over the princess who gave up her royalty in order to see the world with a man. Niino is one of few people who know that Jean has royal blood from the start, observing Jean's relation to the coup from the background until Niino tells Jean himself. Niino went to school with Jean despite being much older than him by faking his age and wearing glasses. Niino's real name is never revealed; Niino is the name he received when he began a new life. Niino's father died in the same train accident that Jean's parents did.