"Atsushi Saito is a major character in the Japanese manga ""Heaven Guards"". He is a young man with short black hair and brown eyes, who is heavily involved in the supernatural world of the series.

Throughout the story, Atsushi is portrayed as a complex and somewhat mysterious character. He is first introduced as a member of a vigilante group known as the ""Heaven Guards"", which is dedicated to protecting humanity from evil spirits and demons. Atsushi is highly skilled in combat and has a keen intuition which allows him to quickly identify supernatural threats.

Despite his serious demeanor, Atsushi also has a softer side. He is shown to be protective of his friends and has a strong sense of justice, often putting himself in danger in order to protect the innocent. Atsushi is also shown to have a love interest in another character in the series, which adds another layer to his character development.

Atsushi's backstory is gradually revealed throughout the manga. He had a traumatic childhood, during which he witnessed his parents being killed by a demon. This event motivated him to join the Heaven Guards and dedicate his life to protecting others from similar tragedies. Atsushi's past also plays a significant role in his relationships with other characters, as he struggles to come to terms with his own emotions and trauma.

In terms of personality, Atsushi is stoic and serious, but has a dry sense of humor that can be surprising at times. He often keeps his thoughts to himself, which sometimes makes it difficult for others to understand him. However, he is fiercely loyal to those he cares about and has a strong sense of duty towards his job as a Heaven Guard.

Overall, Atsushi Saito is a complex and compelling character in ""Heaven Guards"". His blend of martial prowess, emotional depth, and enigmatic personality make him a fan favorite and a key player in the series."