Both movies tackle the dark theme of human trafficking.

Both are BL films about the difficulties that follow a romance between a male prostitute and a closeted gay man.

Both movies are about the first emperor of a unified China, king of Qin. While they have different focuses story wise, they both show his personal and political struggles, etc.

Both movies tell a hopeless love story between a woman and a convict.

Both films detail a young girl who is kidnapped, held captive, and subjected to torture by a single man.

Both films are about the first Emperor of China's Qin Dynasty.

In both films, a terminally ill parent tries to teach his/her intellectually disabled son everything he needs to survive before he/she passes away.

The only theme these two movies share is an innocent man who is tortured into giving a false confession. National Security spends most of the movie showing us the actual process of torture while Box: The Hakamada Case focuses more on showing us the ramifications of such unethical interrogation methods. Both are based on a true story.

Both films portray corrupt police forcing a confession from an innocent man who then spends years in prison. Both are based on a true story.

Both films take place in a mental hospital and show the strong friendships that are formed amongst patients.

Both are old school Japanese dramas that tell the story of a learning disabled man who faces discrimination.

Both dramas focus on the difficulties an intellectually disabled young man must face when abandoned by his family. Algernon Ni Hanataba O focuses more on romance and teaching life lessons to its characters, while Seija No Koushin is much more gritty in its portrayal of society's discrimination against disabled people.