Season 1 of Mirror Twins premiered on April 6, 2019.

Keigo and Yugo play together in a park near their home. Their face look exactly the same, but they are called “Mirror Twins” because Keigo is a right-hander, whilst Yugo is a left-hander, and they have different personalities. At sunset, Keigo asks Yugo to come home together, but Yugo says “No.” Keigo leaves Yugo at the park, and Yugo gets kidnapped. Keigo feels a deep sense of remorse for what happened at the park. 20 years later, an attempted murder takes place and Keigo investigates the case. The only evidence found at the crime scene is the same DNA as his. This makes Keigo to feel that Yugo is still alive and starting his revenge.

Season 2 of Mirror Twins premiered on June 8, 2019.

The acts of revenge are believed to have ended with the suicide of Yugo Katsuragi. However, a year later, the grandson of Kobayakawa, a lawmaker of the Lower House, is kidnapped. Keigo is designated to negotiate with the kidnapper who demands that he brings the same amount of ransom money to the same place for the handover as when Yugo was abducted 21 years ago. Keigo is convinced that this is a copycat case.