|Kanji:||結城 海斗（ゆうき カイト）|
Nami Yuuki (sister)
Kaito Yuuki (結城 海斗, Yūki Kaito) is a young altered man who went willingly into Area D to look for the murderer of his sister. His ability is named Deserted House, giving him the ability to store things within another dimension.
Kaito appears to be in his twenties. Kaito is a slim muscular man with blonde, messy hair that is parted to the right side, and blue eyes. He wears a red scarf and is usually seen without a shirt revealing a well-toned body.
Kaito has a laid back attitude, rarely seen having a serious face. The only time he gets serious is when a young female is involved. At the beginning of the series, he just cared about making a group in order to survive the prison, Area D, to achieve his own personal agenda. However, into the series he is shown to care for his comrades deeply.
Kaito's little sister was murdered by a serial killer and that is his motivation for coming to the island.
Main article: Deserted House
Kaito's altered ability is known as Deserted House (廃屋) . It allows him to store objects of his choosing within another dimensional space. However, in order to store said objects, Kaito must come into physical contact with the object he'd like to store. In addition, he can only store as many objects as equal to the mass of his body. Objects stored by Kaito's ability maintain the same condition as they were when they came into contact with Kaito's body, i.e., an arrow exhibiting the same momentum and/or velocity as when it was released and shot or a canned beverage that was initially stored in a freezer at cold temperatures.
Due to Mariko's resemblance to his younger sister both appearance and personality-wise, Kaito is shown to have brotherly (or romantic) feelings for her, often going against her orders to leave her behind and showing concern when she is injured, despite being a walking corpse.