“I have a responsibility as a parent and as the chief of police.”
Soichiro wears a pair of rectangular spectacles at most times and is a fairly tall man. His appearance fits that of a middle-aged man, and he prefers to dress in formal Western clothing.
Soichiro is a kind man with a strong sense of justice. He cares greatly for his family and the members of the Japanese Task Force. He is a serious and responsible man that gains the respect of many. He has a strong sense of duty, and even after the police stop funding the Kira investigation he continues trying to solve the case with the Task Force.
Soichiro was often absent from his home, meaning that he'd have to spend little time with his family. However, this is in part to his motto, "justice first, family later" (a belief Light ends up adopting).
Throughout the Kira investigation, he believes that his son, Light Yagami is innocent. In order to prove it he goes as far as to kidnap Light (who had given up the Death Note and lost his memories of ever using it) and his girlfriend, Misa Amane (who had also given up her Death Note and had no memories of it), and put them in a situation in which if Light were Kira, Light would have no choice but to kill him.
Thanks to L's accusations of Light being Kira, Soichiro's role as a detective is challenged and so are his deontological values he holds, allowing L to take drastic and illegal measures simply in order to prove to himself that his son isn't Kira, such as when he allowed L to place surveillance cameras in the Yagami household, a move that Soichiro would otherwise detest and disagree with thanks in part to its unlawful nature.
When his daughter Sayu is kidnapped by the Mafia, he becomes conflicted over whether or not he should follow their wishes and trade the Death Note for Sayu. His dilemma comes from having to choose between the duty of an officer, and the duty of a parent. As a police officer and the Chief of the NPA, he believes that handing over the Death Note to the Mafia is wrong, and the Death Note in the hands of the Mafia is too great a risk. However, he ultimately decides that he will make the exchange, not as an officer, but as Sayu Yagami's father.
As the Kira case begins, Soichiro follows L's request of working with him, Kira most likely residing within Japan. As time goes on, much to Soichiro's disappointment, tension rises as more police officers resign and get upset with working with an anonymous figure who makes questionable moves.
Eventually, after the murder of a dozen FBI agents, not only is it clear that Kira kills anyone who opposes him, but L was investigating a secret investigation of them; this causes the majority of the officers to quit, leaving only several. In order to end any remains of distrust, L and the Task Force agree to meet in person, using a specific system involving the switching of hotels. Seeing L in person for the first time, they also see Watari's face, and address L by the name "Ryuzaki." The Task Force agrees to wear counterfeit badges on L's request in order to protect themselves from Kira's power; while the Task Force is dismissive of these kinds of methods, Soichiro is the force that agrees with L and goes along with his plans.
After it's apparent to L that Kira is among those Raye Penber was investigating, he decides to plant surveillance cameras in the Yagami household. Despite it being very unlawful, Soichiro reluctantly agrees to go along with L's plan in order to clear his family.
While surveilling Light, L begins to grow more and more suspicious of him, resulting in Soichiro being deeply offended and anxious. Eventually, L decides to remove the surveillance cameras and wiretaps, but that is not enough to clear Light's name. Soichiro eventually collapses due to the stress of working tirelessly as well as the possibility of his son being Kira. In the hospital, Soichiro talks to L and Light regarding the nature of Kira's identity and Kira's morality.
When the Second Kira airs the tapes using Sakura TV, Soichiro takes initiative and decides to use a police truck to break into Sakura TV's building and retrieve the tapes, giving them to L, despite his condition. Not too long after, L asks Light to join the Task Force, which is when Soichiro begins using the alias "Asahi."
Eventually, Misa Amane is convicted as the Second Kira, and Light is put under immense suspicion and will be held for questioning. Before this is possible, however, Light tells the Task Force that he "might" be Kira, forcing L to detain Light. Soichiro, scared about his son being Kira, tells L to put himself under confinement until Light is released.
Eventually, Light orchestrates a plan involving the erasing of his memories as Kira, and has someone else do the killings, leading the Task Force to pressure L to release Light. L enacts a plan involving Soichiro acting as if he would shoot Light with a gun; however, the gun has blanks, with the rationale being that if Light really were Kira, he'd kill Soichiro. With this, Light is free.
The Task Force, L, Light, and Misa all help to capture Higuchi, the third Kira, leading to the discovery of the Death Note. The Task Force sees the 13-day rule, and Light and Misa are fully cleared; shortly after, Light kills L, and takes his place.
Years later, Mello kidnaps Takimura in exchange for the Death Note, and shortly after, an agent working under the SPK meets with Soichiro and agrees to help the Task Force. Takimura is killed, and Sayu becomes the Mafia's bargaining chip instead. Reluctantly, Soichiro goes through with the trade, and he begins feeling suicidal thoughts from giving the Death Note to a dangerous criminal organization.
Kira then contacts the Task Force and has them use the Death Note and raid Mello's hideout. Much to Light's dismay, Soichiro agrees to use the Death Note and makes the Shinigami Eye Deal, resulting in him learning Mello's name in a standoff against Mello. However, Soichiro is fatally wounded by Jose and Mello's bomb, resulting in him being rushed to the hospital.
There, Light tries to have Soichiro write Mello's name in the Death Note, but Soichiro ends up dying. Before passing, Soichiro saw his son's lifespan absent, proving to him that Light is truly innocent.
His death later plays a major role in the Kira's defeat when Light is exposed in front of Near, the SPK, and the Task Force, resulting in Matsuda, who was enraged at the fact that Light was the one who drove his father to death in a cold-blooded fashion, shooting him multiple times to prevent him from using his snippet Death Note hidden within his watch (ironically a watch given to Light by Soichiro himself).
In other media
Soichiro's role in the film series is essentially the same, although Death Note: The Last Name departs significantly from the manga. Ryuzaki manages to expose Light as Kira in front of the entire Task Force including Soichiro, and Soichiro saw Light's attempt to write down his father's name. Light tries to convince Ryuk to write down the names of the Task Force members, and Ryuk writes down Light's name. Light dies in Soichiro's arms begging him to believe that he acted as Kira for the sake of justice.
In the Matsuda short film, Matsuda is having trouble getting closure in the case. Soichiro gets a note to Matsuda for him to visit Ryuzaki, and Matsuda does so. In the main films, Soichiro visits L shortly before his death to report on the end of the case, and L apologizes for failing to save Light. Soichiro salutes him on his way out. A year later, on Light's birthday, Sayu fetches Soichiro from the train station, and she believes the story he told her that Light was killed by Kira.
Soichiro's role in Death Note: The Musical is generally the same as in other adaptations, although the Musical has some changes to the story. After receiving the reports of criminals dying, Soichiro makes the call to bring in L to assist on the case. He is openly disapproving of L's extreme methods. L sacrificing Lind L. Tailor crosses a line for him, which he discusses with Light. When Misa is apprehended, he calls L out on her treatment directly. However, Soichiro comes to realize that Light is Kira. He survives his son and silently mourns for him in the final song.
Takeshi Kaga, who plays the character in the films, reprised his role for the 2015 Japanese production. Tetsuya Bessho (別所哲也) will portray the character in the 2017 Japanese production. Lee Jong-Moon (이종문) portrayed the character in the 2015 Korean production, and Seo Young-Ju (서영주) portrayed the character in the 2017 Korean production.
Soichiro performs the following songs:
- Don't Cross That Line is the song Soichiro sings about his disapproval of L's methods regarding his sacrifice of Lind L Tailor to find Kira. Light joins into the song briefly as well.
- Secrets and Lies is an ensemble song with L and Light about the progress of the case.
- Honor Bound is the song Soichiro sings when he begins to accept that Light might be Kira.
Soichiro's role in the television drama is generally the same as in other adaptations, although the story has major changes to the plot.
Prior to the beginning of the series, Soichiro is out working a case and does not make it to the hospital when his wife's condition worsens. Sachiko Yagami dies in the hospital, with Light and Sayu alone with her. This causes a rift between Light and his father, and Light loses his dream of becoming a police officer.
At the beginning of the series, Soichiro trades himself for a hostage and is held at gunpoint. This prompts Light to intentionally kill the criminal with the Death Note to save his father's life, which leads Light to realize that the notebook can be used for justice. This event is one of the reasons that L suspects Light, and when L points it out to Soichiro, Soichiro begins to suspect his son as well.
Soichiro definitively discovers that Light is Kira when he comes across Light shortly after Light retrieves the Death Note that was taken by Mello and Shoko Himura. Light lies and says the Death Note isn't real, but Soichiro knows it is and writes his name into the notebook, perhaps in part to see if Light would stop him or let him die. He then tries to set it on fire, but Light fights him for it much more aggressively than he tried to stop Soichiro from writing his name, showing how far Light's become devoted to Kira over his family. Soichiro dies of a heart attack before he is able to successfully burn the notebook, and Light pries the notebook out of his dead father's hand.
Yutaka Matsushige portrays Soichiro in the television drama.
Soichiro's character is renamed James Turner in Netflix's Death Note American film, and he is portrayed by Shea Whigham.
- “Only those who are ready and willing to sacrifice everything and fight, who are truly committed to stopping this psychopath… are asked to remain. I'll find out who you are when I return at five o'clock from my meeting upstairs.” (Chapter 10)
- “Kira is evil, there’s no denying that. But lately I've been starting to think of it more like this. The real evil is the power to kill people. Someone who finds himself with that power is cursed. No matter how you use it, anything obtained by killing people can never bring true happiness.” (Chapter 22)
- “I'm sorry, Sachiko.” (Chapter 67)
- “Light... I trust you.” (Chapter 72)
- “I...I'm sorry... I couldn't kill him after all.” (Episode 29)
- “I will not succumb to evil.”
- “Light was murdered by Kira…” (L: Change the WorLd, p 185)
- “Ryuzaki… you're back.” (L: Change the WorLd, p 186)