Brother's Heart

Kazuki, a young man scarred by the disappearance of his brother Shizuki, who was kidnapped during an important conference they attended with their parents, has dedicated his life to becoming an exceptional investigator. Alongside his best friend Junya, who is also searching for answers about the abduction of his sister, Kazuki has successfully solved numerous criminal cases. One day, their chief assigns them a delicate case: an investigation into "Black Ruby," an elusive gang specializing in stealing precious items. Until now, this group has never left a trace, but during a botched heist that escalates into a shootout, one of the criminals is injured. The team manages to recover a blood sample, a first in the case. However, when DNA analysis reveals that the blood belongs to Shizuki, Kazuki’s long-lost brother, the shock is overwhelming. Although Shizuki has changed his name, certain physical traits confirm his identity. This discovery rekindles the hope of Kazuki and Junya to find their kidnapped loved ones but complicates their mission. Meanwhile, Kazuki struggles with his personal life. His relationship with Mayu, his jealous girlfriend, grows increasingly strained. Mayu views the budding connection between Kazuki and Hyorine, a resilient colleague with a painful past, with suspicion. Hyorine, whose younger sister was also abducted in the past, shares a deep bond with Kazuki and Junya through their shared pain and quest for justice. As the investigation progresses, tensions rise: Mayu, consumed by fear of losing Kazuki, starts making mistakes that risk jeopardizing the mission. On the other hand, Kazuki faces a moral dilemma: continue pursuing "Black Ruby" to bring them down or do everything in his power to save Shizuki, even if it means sacrificing everything. Amid betrayals, revelations, and difficult choices, Kazuki, Junya, and Hyorine must join forces to confront a truth far darker than they ever imagined.