__Height__: 181cm
__Race__: Part-Human, Part-Gear  
__Professional Status Occupation__: Bounty Hunter  
__Weapon__: Flag   

Sin is the son of Ky Kiske and The Maiden of the Grove. He travels with Sol Badguy for most of the game. He does not seem to get along with his father very well. However, he appears to have a very deep love for his mother. He has an eye patch over his right eye for unexplained reasons. His hobbies include searching for novel adjectives and overcoming his dislikes one at a time. He dislikes people who aren't willing to overcome their dislikes, being treated like a child, and the United Kingdom of Illyria.

As a child, he was kept on a chain by Sol, and always carried his favorite stuffed animal Chimaki with him. He is the target of the antagonist Valentine, since his Gear cells allow him to be The Key to open and unlock The Cube.   

He feels uncomfortable in orderly situations and is not too good at social dispositions. On the contrary, his personality that doesn't look back on what's done may seem insensitive, but his simple and innocent personality can be refreshing. He also has an optimistic and cocky side to him. He also considers his appetite as something important to him, as "he cannot say the other one."   

Over the past couple of years, he has been traveling with Sol as a bounty hunter and has overcome many hardships. He trusts Sol and looks up to him as a father, a friend, and a teacher. He is currently enjoying his journey. 

After the decline of the once robust fields of science and technology, a new energy source known as magic fuels the modern era. Humanity creates forbidden biological weapons: Gears. Those Gears eventually stand against humanity in a rebellion. Although they manage to overcome in the struggle for survival known as the Crusades, humanity’s losses are so great that even after several decades pass, their emotional wounds remain unable to fully heal. Sin Kiske, the child of a human and a Gear, heads to his father Ky and mother Dizzy’s wedding ceremony. Their wedding breaks the ultimate taboo: a union between a human and a Gear. Even with the world at peace, it took many years for such a ceremony to come to fruition. Despite the complex array of emotions surrounding it, the wedding ceremony is met with blessings. When suddenly, a mysterious girl appears… The fated child inheriting Gear blood–and the mysterious girl who despises Gears. Their meeting would shake the world.<br><br>
(Source: YouTube Description)

Set in the year between the events of the first two games, the story revolves around two new characters exclusive to the manga: Tyr and Mizuha, and the mystery of severed Gear parts falling from the sky.  Members of the Post War Administration Bureau (P.W.A.B. for short) - the secretive organization responsible for many events in the games - serve as the antagonists of the story.  Characters from the games, such as Sol, Ky, Axl, Potemkin and Kliff, also appear, albeit with relatively minor roles.