Mayu Ootsuka is a member of the Public Security Bureau of Foreign Affairs, Section 4, of the Tokyo Metropolitan Police. This is the division of the police that is most important to Darker than Black because Section 4 specifically deals with Contractor-related cases. Thus, all the members of Section 4 are directly related to Hei's story. Mayu is no different. Her role in the division is significant because she serves as the liaison to the astronomy division, which keeps track of the Contractor star related activities. Without Mayu, it would be much harder for Section 4 to operate sufficiently and do their jobs.

As we said, Mayu's role in Section 4 is very crucial to the operation and efficiency of the division, which makes her a very important character. Beyond that, though, Mayu serves as an excellent source of comic relief in a very dark story, because outside of work she is an otaku who writes strange fanfiction. She is even central to an entire "spoof" style episode of the anime where Hei stars as a main character in her latest fanfiction, unbeknownst to her that he is the Contractor she is constantly searching for at work.

Mayu is great for giving everyone something to smile and laugh about, and perhaps even a character that some viewers can identify with easier than others. She may not have much screen time outside of that episode, but she deserves to be on our list of Underappreciated Darker than Black characters all the same.

Nick Hillman is one of the few friends that Hei makes throughout the series. Hillman works at PANDORA, and Hei meets him when he infiltrates under the cover of just being a janitor. He soon discovers that they both have a common interest in telescopes and stargazing, with a dream to see the "real sky" someday, and become friends quickly. As more of his story is revealed, it turns out they have even more in common - Hillman is a Contractor with the ability to manipulate electricity, just like Hei. He tries to hide this about himself to keep Hei, who he believes to just be an ordinary citizen, safe and uninvolved. In the end, the two end up fighting over an artifact and the truth is revealed.

Hillman might seem like nothing more than a minor character, but he is very intriguing and he still plays an important role. Whereas Contractors are not meant to display emotions, Hillman had very real ambitions and goals that are revealed throughout his time in the show - though an answer to why is never given. He also allows Hei to show his more human side by befriending someone and talking about his very normal interest in astronomy, highlighting a side of Hei that is often overshadowed by his role as an assassin and deadly Contractor. He is also the only other Contractor revealed to have the same ability as Hei, though, his does have a very clear remuneration while Hei's does not.

Yuusuke Saito is another member of Section 4 of the Foreign Affairs Bureau, and one of the direct subordinates beneath Misaki Kirihara. He is an officer in the division that is tasked with carrying out important and dangerous missions dealing with Contractors including undercover work. However, despite these assignments, Saito seems to lack common sense. For example, he goes undercover while using his real name! He means well though and fights hard in the name of what he feels is right, and always looks out for his fellow officers however he can.

When one remembers Section 4 in Darker than Black, one usually only thinks of Kirihara herself and never her underlings. However, without people like Saito, Kirihara wouldn't have a team and wouldn't be able to do anything! Saito is one of her main supports and is in the anime regularly as a side character. He is one that you aren't likely to completely forget but definitely doesn't get the appreciation he deserves for his loyalty, support, and the occasionally humorous situations he finds himself in.

Yutaka Kouno is Yuusuke Saito's partner, and thus another member of Section 4. He also directly reports to Misaki Kirihara, though he doesn't treat her with the same fear and respect his older partner does. Kouno is presumably the youngest member of the team and often acts like it. While he does get the job done and serves as a formidable officer, more often than not Kouno's light-hearted, more immature attitude and demeanour are there to add some humour to an otherwise serious and sombre police station. Like Saito though, there is more to Kouno than just being a comical outlet - he also is critical in Section 4 missions and helps make the team a worthy adversary for the Contractors.

Yutaka Kouno is definitely worthy of mention on our Top 10 Underappreciated Characters in Darker than Black. He is in the show fairly regularly, almost as often as Kirihara is. Just because he is in the background it doesn't make him any less important. Beyond being the comic relief in the division, which does make him cool and important already, he is yet another critical member of the team. Without Kouno, Section 4 would not be able to do the things that it does - and arguably would be a much more boring place, with not much else to lighten the mood!

Havoc is a Contractor like Hei, and the two have a history together during the incidents surrounding the Gate in South America. However, unlike Hei, when the Gate there disappeared Havoc lost her powers and many of her memories. For a long time, she lived with a family in Romania and learned how to enjoy the simple things in life like cooking and being with children, who she discovered she loved. She eventually is discovered and brought back to PANDORA though and learns the horrible truth that her remuneration used to be drinking the blood of children - but in return she had a powerful ability to create a vacuum that killed thousands in South America, making her one of the most notorious Contractors ever.

Havoc may not be in many episodes but she is a very important and cool character none the less. She reveals more of Hei's mysterious back story, even alluding to a potential past relationship or at the very least friendship. She tells the viewer that he had become more emotional, and talks more about Hei's ties to his sister. Her own personal struggle to come to terms with who she is now, and who she used to be, reveals a very emotional and human side to Contractors that we don't usually see. It makes Havoc interesting and believable and gives a different perspective to Contractors than many of the others ever reveal.

April is a key member of the MI6 division that comes to Tokyo consisting of herself, her partner November 11, and a doll named July. April's power as a Contractor is to manipulate water, and when paired with November's power to freeze, they are a deadly duo when fighting together. She also has the ability to surround only a person's head in water, personally drowning them. She is constantly fighting against Hei and is a very serious enemy that he must face - even if he does eventually defeat her.

Because April dies much sooner than November or July, she is a less memorable character than her counterparts. However, it doesn't make her any less cool! April is great at fighting and makes a fantastic partner for November, and they cause quite an obstacle for Hei to have to overcome. She also loves her remuneration, which is rare amongst the Contractors - but that is because her payment is to drink beer, and she loves alcohol. April's very demeanour is cool and casual, displaying her as a confident and strong woman - and being able to hold her own against Hei, even if it wasn't forever, shows that her self-confidence was not misplaced. When you remember MI6, be sure to not forget about April!

Amber is the first known Contractor, and has the ability to freeze and rewind time. If she uses her ability enough she can even foresee future events so that she can respond appropriately to them. With such a strong power, her remuneration is also high - she ages backwards, appearing younger and younger, and that means she has a limit to how many times she can use her power. Amber had changed organisations many times, including fighting in South America alongside Hei and Bai, but spends the majority of Darker than Black as the leader and founder of Evening Primrose. Despite fighting in opposition regularly to Hei as she works towards her goal of destroying the Gate without killing all Contractors, she does her best to protect him and keeps her people from harming him no matter what.

Being the first Contractor already makes Amber significant, and her power is undeniably cool. But beyond those things, Amber is a central character to the story told in Darker than Black. She and Evening Primrose are always fighting against the Syndicate and trying to bring down the Gate, and in the end, she sacrifices herself to help lead Hei towards an option that would do so without killing all Contractors and destroying Japan. Her feelings for Hei are clearly strong and persistent despite his cold feelings towards her since she changed her allegiance after South America, showing a deep commitment and touching story amidst a much darker plot.

Aside from all the big name security operations operating in Darker than Black, there is also the private detective Gai Kurasawa and his assistant Kiko Kayanuma, who had earned her place on our list of the Top 10 Underappreciated Darker than Black Characters. Kiko is a massive anime fan and cosplayer, but despite having what might be seen as an air-headed and overtly flamboyant personality, she actually had a strong business mindset. Kiko is always more concerned than her boss about their business' financial situation, which is often dire, and will do anything to help them earn the money they need.

Kiko Kayanuma is a character that shows up at random intervals throughout the story of Darker than Black, mostly in OVAs, and while she is a source of comic relief she is also significant to showing different sides to characters and developing their personalities. For example, she tries extremely hard to befriend Yin, despite Yin's lack of emotion, all the way to including her in cosplay. She also lusts after Hei on a regular basis without knowing who he is beyond his false daily identity. She sometimes shows up in the middle of his missions in some way or another, adding another element to them or at least breaking up the dark tone with something light-hearted. Her role as the exaggerated fan girl also gives her the chance to say what many viewers might be feeling or thinking about the show and its characters, putting Kiko in a very interesting position.

Bai is Hei's younger sister and a very powerful Contractor. While the full extent of her powers is never explored, it is eluded to that they go far beyond just the power to control electricity. On top of that, she also excels in molecular reconstruction. Bai is the Contractor responsible for the destruction of the Gate in South America prior to the beginning of the anime and has since disappeared. It is later revealed that the reason that Hei, previously only a bodyguard to his little sister, became a Contractor with her electrical power is because Bai still exists through him by using her molecular reconstruction ability to form a fusion.

Bai is never actually seen in the series because she had disappeared before it started, but that doesn't make her any less significant. Without Bai, Hei would not have any of his powers and wouldn't be in the Syndicate, let alone a powerful Contractor. Bai's destruction of Heaven's Gate is the backdrop for the story told in Darker than Black, and without it, the story wouldn't be at all the same. She has an incredible impact on the story without ever being present - though she is mentioned quite regularly at least. And on top of her significance to the story, Bai was an extremely powerful Contractor, and the fact that she destroyed the Gate is pretty cool too.

Like everyone in Hei's immediate group tied to the Syndicate, Huang's name is a cover alias derived from the Chinese word for a colour, and Huang's is yellow. He is the leader of their group and their essential contact directly to the Syndicate. Aside from his role as a leader, he also shows up fighting when necessary and is responsible for saving the lives of many of his team members. Huang has a dislike for both Contractors and Dolls due to his rough personal history with them, but works with Hei and Yin anyway - at first because he has to, but arguably later because he wants to.

Huang is far from the usually attractive, young important male character that is in most anime - in fact, he's quite the opposite. Huang is a middle-aged, heavier set man with a gruff voice and far from an attractive face, usually wearing a trench and old beret while smoking a cigar. This alone can make him a forgotten character for many people when they are discussing their favourites or who was the coolest or most desirable, but in reality, Huang is one of the most important characters. He is central to the plot of the show as the leader of Hei's group and the one directly in contact with the Syndicate leaders. He makes most of the decisions, gets the new jobs, and deals with any trouble that might arise. Without Huang, Hei's group wouldn't be able to function so he hardly deserves to be a forgotten character! He may not be pretty, but Huang is so important to Darker than Black that he easily is our number one underappreciated character.