Tsugumi Ohba and Takeshi Obata's supernatural crime thriller series Death Note is largely about the battle of wits between Light and L, and this story has also been told in live-action movies from both Japan and the United States. While Light and L dominate the story, supporting characters like Soichiro Yagami, Light's father, are not to be underestimated.
It's true that Mr. Yagami doesn't have his son's genius intellect, but he's a capable police chief, and he's proven himself in many impressive ways. Soichiro Yagami undergoes a few particular changes through the series, but in other ways, he's the same heroic father we've come to know and love. In what ways is Soichiro a dynamic character?
10 Changed: Body Weight
This seems like a pretty minor detail to discuss, but sometimes, it's the little things that make all the difference. At first, Soichiro is pretty comfortable in his career, and he had never faced a challenge like the Kira case before.
Mr. Yagami is well-built at first, but over time, he loses a lot of weight due to stress, and ends up with hollow cheekbones and a skinny physique. That, and his tired eyes and stubble, make clear that Kira is taking a real toll on him.
9 Same: Conviction
Soichiro is a lot more like his son than some fans might realize, though both Yagamis might express those shared traits in different ways. Just the way Light is 100% certain that he "is justice," Soichiro feels the same way about himself.
Never once does Soichiro doubt the police or the virtue of the law, and he stubbornly refuses to break the law or illegally use a handgun. To him, law and order are guiding lights, and he'll follow them through any darkness with confidence.
8 Changed: Hair Color
Soichiro has slicked-back dark hair, and he looks professional but stylish when he first appears. But the stress of the Kira case not only makes him lose weight, but it also made him go gray early. That's been known to happen to people, such as world leaders.
By the time Mello and Near begin their operations, Mr. Yagami's hair is mostly gray, with some streaks of his dark hair color in it. It's an astonishing transformation, and it's not just because of his age. He shows his fatigue from head to toe.
7 Same: Good Dresser
This is a live-action version of Mr. Yagami, and like in the anime, he dresses to impress. He's always wearing a crips suit to work, and he wouldn't dare get caught with his shirt untucked or his shoes unshined.
Even at home or in civilian life, Mr. Yagami looks his best, preferring fancy slacks and button-up shirts. In fact, even his sleepwear is somewhat like a suit, including long sleeves and pant legs. He's not the type to sleep in a tank top and patterned boxers.
6 Changed: Belief In Shinigami
At first, shinigami like Ryuk and Rem were totally unknown, since they are invisible and the human world has largely moved on from such superstitions. By now, a shinigami always takes someone by surprise when they appear.
Soichiro had no reason to think that death gods exist, but he really changed his mind (like the other police did) when they captured Higuchi and laid eyes on Rem. Soichiro adjusted pretty quick, though, and was soon talking casually to Rem.
5 Same: Stubborn Streak
This is another trait that Soichiro clearly shares with his son Light, not to mention his fellow detective L. All three of these characters are firm in their beliefs and ideas, and they won't let anyone get in their way.
Soichiro refuses to let go of his "hero cop" attitude, and he won't let his allies fight Kira alone while he's bedridden. Even after suffering a heart attack, he leaped out of bed to keep fighting, and didn't go back (more on that soon). Nothing keeps him out of the fight for long.
4 Changed: Powers
Most of the human characters in Death Note are just that: human. They have no abilities that the shinigami boast, though they can use the notebooks to kill other people and dictate realistic terms for those deaths.
But there is always the eye trade, and Soichiro made that deal with Ryuk. He can now see people's real names and lifespans, a precaution for the raid on Mello's hideout. He learned Mello's real name, but failed to actually write his name.
3 Same: Family Love
This is one of Soichiro's most admirable traits. He's not only a hardened detective, but a loving family man, and he puts his family before himself. He has a wife and two children to look after, and he's determined to help restore a Kira-free world for them.
Tragically, his own son was Kira, but he never learned that fact. Soichiro and his wife Sachiko were a team in the long haul, despite the dangers, and Soichiro went to great lengths to rescue Sayu from Mello early in the second story arc.
2 Changed: Temper
The enormous stress of the Kira case took a toll not only on Soichiro's body, but also his mind. He never stopped believing in good, and he never gave up on the Kira case. But he did become more snappy and brittle over time.
At first, Soichiro was rather stoic and calm during any event, but he snapped at the other officers when they objected to planting cameras in his house (Soichiro wanted the job done, period). He also got pretty tense on the phone with Mello later on, and he sometimes acted tensed around Rem, too. He's become pretty jumpy.
1 Same: Action Hero
At first, Soichiro had no need to throw himself right in harm's way to fight Kira, but he soon did. When Misa broadcasted herself from Sakura TV as an imposter Kira, Soichiro took it upon himself to drive an armored van right into the studio to stop that broadcast.
Later, Soichiro personally led the raid on Mello's hideout, complete with body armor, firearms, and a protective helmet. Shots were fired in that base, and Soichiro didn't take a scratch until he confronted Mello and was shot from behind. He's not afraid to get his hands dirty in the name of the law.