In the year 2021, mankind fought the Gastrea and was defeated; and are forced to live within monolithic walls made of Varanium, a material that is capable of subduing the Gastrea. However, despite humanity's defeat, civil securities are established to combat the Gastrea with "cursedchildren" as the "initiators," who are paired with "promotors" to help lead them.The story focuses ten years after the war with Rentaro Satomi, a promoter of the Tendo Civil Security founded by his childhood friend, Kisara Tendo. Rentaro is paired with EnjuAihara, a cursed child and his initiator with severe trust issues. Together, they protect the Tokyo area from the threats of the Gastrea.Black Bullet is an ongoing light novel series written by Shiden Kanzaki with illustrations done by Saki Ukai published under the Dengeki Bunko label. A manga adaption was published in 2013 in the Dengeki Maoh magazine.An anime adaption has been green-lit for the Spring 2014 anime session produced by Kinema Citrus.Available for streaming at Crunchyroll for viewers living in the following areas: USA, Canada, UK, Ireland, Australia, New Zealand, South Africa, Netherlands, Scandinavia, Turkey, Latin America, Italy, Spain, Portugal, the Middle East, the Arab League, France and Dom/tom, Belgium, Switzerland, Andorra, Luxembourg, Algeria, Tunisia, Morocco. Note that there is a 6 month delay for French-speaking territories.Licensed by Sentai Filmworks for home video release in North America.
Tropes in "Black Bullet" include:
Absurdly Spacious Sewer: In episode 2, Rentaro encounters an older gentleman raising several homeless cursed children in an absurdly spacious and absurdly cozy-looking sewer.
Achilles' Heel: Varanium is a metal that is capable of subduing or harming the Gastrea and the weapons used by Initiators and Promotors are made from it. It is not strong enough to stop a stage V Gastrea.
It's also used against cursed children as well since it's capable of stopping their Healing Factoras evidenced with a bomb packed with Varanium shards used to kill a group of cursed children that Rentaro taught to in the anime. Some cursed children with high corrosion rates, like Enju and Tina, are more likely to feel nausea and sick when near Varanium monoliths or in Varanium mines while others with low corrosion rates like Hotaru feel no effects.
Action Prologue: The opening of the anime shows a young Rentaro huddling with a crowd of people as two fighter jets fly overhead. One of them is shot down shortly after disappearing into the clouds, while the other one tries to fire at a flying Gastrea. Combined with some anti-aircraft fire from the ground, they seem to manage to shoot the Gastrea down and it lands right in front of Rentaro.
Adaptation Distillation/Compressed Adaptation: Because the anime production team tries to adapt the first four volumes of the light novels into 13 episodes, many of the exposition (most of the exposition are either tied to the plot or World Building) and some of the characters' backstories in the light novel were cut out and removed. Some scenes in the light novel were also drastically altered, toned down, and changed. For example, the group of cursed children that Rentaro taught to were killed by a bomb in the anime. In the light novels, however, they were killed by an angry mob of civilians that Rentaro protected.
All of the Other Reindeer: The cursed children are treated as trash within society due to the fact that they are born with Gastrea virus in their blood. Public flogging and lynching on cursed children is common and most of them live in poverty unless working with civil securities. Police Brutality against cursed children is very common and segregation on cursed children is disturbingly in Jim Crow law levels.
In volume 3, The treatment of the cursed children in other countries is revealed to be much worse than how the Tokyo government treats the cursed children. In other countries, cursed children are used as prostitutes, slaves, entertainment, products, and soldiers. This is especially true in the Middle East due to the fact that Arab culture is a male dominant society. America and England have high ranking initiators where they forced their cursed children to train and unlock their "fields" (an extra ability that a cursed child may rarely develop) and subject their cursed children into horrendous experiments. As Sumrie noted, the cursed children in Tokyo have it good since the government usually leave them alone.
Always Female: There are no male cursed children. The light novels do not provide a full explanation, however in the manga, Matsuzaki speculates it has something to do with the Gastrea virus intervention before the cell specialization stage of an embryo.
And Then the Cursed Children Become Gastrea: A really huge Tear Jerker is that this is the eventual fate of the cursed children is that because they are born with the Gastrea virus, they'll eventually turn into Eldritch Abomination. The rate of erosion varies from each cursed child (if the erosion rate is 50% or above, the cursed child can no longer maintain her human form). However, the virus will accelerate if they use their abilities more and more. Rentaro suffers a bad Heroic BSOD when he had to Mercy Kill Kayo Senju and fears the same fate will happen with Enju Aihara.
An Arm and a Leg: Kisara does this to her older brother in episode 13, slicing off both of his legs with one of her attacks.
Animal Motif: The model initiator that each cursed child are tied to a particular animal based on what they excel at. Enju is the model rabbit due to her emphasis of lightning reflexes, Kayo is the dolphin due to her intelligence (her IQ is 210), and Kohina is the mantis because she preys on her victims with twin swords.
An Offer You Can't Refuse: Kagetane offers an alliance with Rentaro in episode 2, and even gives him a suitcase full of money, trying to win him over with a Not So Different speech regarding wanting to protect the girls from humans who view them with hostility. He understandably refuses, since he doesn't share the same view of wanting to start another Gastrea war as Kagetane. As a possible consequence of his actions, Kagetane tells him to pay attention to Enju's school the next day. She runs away after the school finds out that she's a cursed child, likely because Kagetane told them, forcing Rentaro to go looking for her, but isn't able to find her.
Anyone Can Die: And yes, we do mean anyone. The author has a habit of introducing new characters and killing them off in the same volume or later.
Currently, out of all the developed characters, Kayo, Shogen, Midori, Shoma, Nagasama, Suibara and Hotaru are all dead. That is roughly half of the developed character that isn't a direct enemy.
Armor Is Useless: In episode 9, Rentaro and Enju spot a guy wearing some heavy armor. He tells her someone wearing that much armor trying to fight Gastrea would be more of a burden since the armor is going to weigh him down, and make him less mobile in a fight where speed is key. Sure enough, a few moments later that guy is found dead on the outskirts of the tent city, his armor having been breached through.
Aren't You Going to Ravish Me?: Enju basically invites Rentaro to do this to her at the end of the day in the first episode, but he instead decides to sleep instead. She gets a little angry at that response, and goes into his room and beats him up a little bit.
Artificial Limbs: All of those who are subjected to the "New Human Creation Plan" have their body parts replaced with mechanical ones made of Varanium. They were originally created to fight the Gastrea before the emergence of the Cursed Children. Rentaro is one of them, having lost his right leg, right arm and left eye due to protecting Kisara from a Gastrea when they were children.
A sniper attempts to take out Seitenshi in episode 5. Fortunately for her, she hired Rentaro as a bodyguard, and Enju even manages to kick and deflect one of the oncoming bullets away from them. Her other bodyguards attempt to get her into a building away from the sniper, but Rentaro is Genre Savvy enough to realize the sniper has already fled due to failing to take out their target. Said sniper turns out to be Tina Sprout, whom he had met earlier in the episode, though at the time neither one of them knew about the other being present at that scene.
Rentaro foils two more assassinations in episode 6. One more on Seitenshi, and another on Kisara. He finds out who the assassin is when she attacks Kisara.
Commander Gado becomes one in episode 12 after he's killed in the latest Gastrea attack. He was the leader of the Security teams tasked with defending the monolith breach, and sends Rentaro on a Suicide Mission to kill Pleiades, a Stage 4 Gastrea, by himself.
Kisara's brother in episode 13. She finds out that he deliberately didn't use enough varanium while building the monoliths, which allowed the Gastrea to breach one of them, and causing the Third Kanto Battle to occur in which many people died to keep the Gastrea out of Tokyo. He then used the money he to obtain his position within the government, safe from the dangers posed by the Gastrea.
Badass Adorable: The cursed children who work as Initiators are basically this. Specific mention to Enju Aihara.
Bad Powers, Good People: The cursed children are born with the Gastrea virus in the blood. Despite of this, Enju is a kind-hearted 10 year old girl who wants to protect people she care about with her powers.
Bedmate Reveal: Kisara pulls back Rentaro's bedsheet to reveal Enju sleeping at his side ever since he was in the hospital in episode 3, after barely recovering from an attack by Kagetane and Kohina.
Generally whenever a cursed child shows up to fight Gastrea. Since the police lack the means to fight them effectively, they often have to resort to people like Rentaro and Enju.
Enju shows up to protect Rentaro from Kohina in episode 2.
Rentaro pulls one for Kisara in episode 6 when an assassin attacks her in their office.
Boom, Headshot: The little girl arrested by the police gets subjected to this in episode 2. Thanks to her Healing Factor, she recovers from it after the police had already left, and Rentaro takes her to a doctor.
Boring but Practical: After the barrels on the assassin's gatling gun is chopped off by Kisara's katana, the former simply tries to club her with it. She does manage to get a hit on the latter, knocking her across the room and taking the wind out of her. The assassin also simply tries to choke Kisara after the latter notices she's very hesitant to shoot her at point blank range.
Breather Episode: Episode 8, while it has some action in the beginning and end, for the most part is mostly comedy at Rentaro's expense.
Buxom Is Better: Any girl who's after Rentaro is jealous of Kisara's boobs.
Casual Danger Dialogue: In the first episode, Kagetane Hiruko is seen talking on the phone. He then beats Rentaro down, and when some police officers show up, he shoots them after they try to open fire on him. And even when Rentaro manages to land a hit on him, he just simply turns his head back around, and goes back to his phone call as if nothing happened.
Cat Fight: Kisara and Miori have one in episode 5, after the former draws her sword out of jealousy at the latter while she's happily teasing Rentaro in his apartment during dinner. Miori pulls out a gun and has a folding fan in her other hand. Rentaro and Enju, on the other hand, don't stop the fight; instead they just move the table from the living room into the hallway so the girls don't spill the food on it during their fight. He later laments that he won't be getting his security deposit back after some bullet holes appear on the outside of the apartment along with the lights going out.
Clear My Name: The entire plot point in light novel volume 5 and 6. It involves Rentaro being accused of murder.
Comically Missing the Point: While they attempt to look for more people to join them in episode 9, Enju spots a guy wearing some medieval armor from head to toe, and says they should recruit him. However, Rentaro says someone who's focusing that much on defense wouldn't last long against the Gastrea, and says they should find someone who's less encumbered and can therefore dodge better. She then points to a muscular guy wearing nothing but some wrestling shorts and a mask, which Rentaro also rejects.
Could Have Avoided This Plot: The Fugitive arch in volumes 5 and 6 and suffering Enju and Tina had to endure could have been avoided if Rentaro had allowed Kisara to help clear him while he was in jail. But keep in note that Rentaro had witnessed the main antagonist forcefully kissing Kisara and Rentaro himself is a utilitarian.
Crapsack World: Oooohhhhhh boy. Not only does humanity live in constant fear of the Gastrea, the cursed children who are born with the virus are treated as trash by humanity.
Rentaro suffers a few from Kagetane during the latter's arc.
Rentaro also gets easily defeated when he's forced to fight a Cursed child, Tina Sprout. It's only because his opponent wasn't evil at heart and was hesitant to kill him, allowing a flashbang to disorient her long enough that he managed to survive at all.
At the beginning of episode 11, as the Japanese army fights the Gastrea attempting to penetrate the breach, the fighting seems to have stopped. As they wonder if they won, a tank comes hurling in their direction, followed by some large explosions where the fighting was earlier, and then a lot of Gastrea heading in their direction. In fact, were it not for the Aldebaran Gastrea suddenly calling off the attack, they likely would have overwhelmed any resistance put up by the remaining humans, despite the effort by Rentaro and his group.
Cursed with Awesome: Cursed children are born with the Gastrea virus, but they also can manipulate the virus to gain superhuman abilities. Subverted that overuse of abilities accelerate the virus's erosion rate faster.
Defeat Means Friendship: The Katagiri siblings in episode 8 won't work with Rentaro unless he can defeat them in combat. While Rentaro has some trouble with Tamaki, Tina completely dominates Yudzuki, the latter being unable to even lay a finger on her. However, they keep their promise to help him with the latest threat.
Delayed Reaction: Rentaro has one at the end of episode 7 when he wonders about Tina's fate. He's offered a glass of water by Tina, thanks her, and drinks it. Then does a Spit Take when he realizes Tina is there.
Depopulation Bomb: The light novel mentions that there are only 750 million humans left in Earth after the Gastrea war. To put this into perspective, the world population in Real Life right now is 7 billion.
Done again in episode 13, this time with Shoma against Aldebaran. Unfortunately he also died as he finished what Rentaro had intended to do, punching Aldebaran so hard that the bomb inside of it would then detonate due to the sheer force of impact.
Dull Eyes of Unhappiness: Enju displays some in episode 10, after she sees the dead bodies of the girls Rentaro was trying to teach, killed in a bomb attack.
Eldritch Abomination: The victims of the Gastrea virus eventually turn into horrendous monsters that attack anything in sight.
Empathy Doll Shot: One is seen in episode 10, when Rentaro returns to the area where he was teaching the Cursed Children...
Enemy Mine: Rentaro is sometimes forced to work with others who don't exactly get along with him for a variety of reasons. However, due to the very real threat of Gastrea, he often tries to put aside his differences to work together with them. And in episode 11, said person helping him this time is Kagetane, who kills some Gastrea attacking him, and tells him where a Stage 4 Gastrea is at. When Rentaro wonders why they're following him, Kagetane simply states they just happened to need to head in the same direction as him.
Evolving Credits: Around episode 6 the new opening sequence replaces some of the visuals from the earlier opening credits, such as the three spinning lights at the beginning with a shot of Rentaro, Kisara, and Enju instead.
Ending also gradually changes, although not in content: scenes change from static pictures to animations. Most notable is from ep2 to ep3 (transition from Enju looking at the flower to submerging), but further episodes add more.
Eye Scream: Rentaro and Tina run into a Cursed child standing around panhandling and singing with her eyes covered in episode 8. They ask her about that, and she removes her bandages, while the two have a horrified reaction, particularly after she tells them she poured molten lead to get rid of her red eyes which caused her mother to abandon her and her younger sister.
Fantastic Racism: The cursed children are treated as trash by many humans. Even Rentaro in the light novel held some racist grudge against the cursed children prior to meeting Enju.
If you think the treatment of the cursed children can be bad enough, wait till you hear a bill from the Tokyo government where they will strip the cursed children their citizenship.
Humanity's battle against the Gastrea falls into this. Every defensive victory against the Gastrea results in more loses that humanity is unable to recover (particularly the human loss).
In episode 8, Seitenshi tells Rentaro that one of their monoliths keeping the Gastrea out is failing. While they are already working on building a replacement, it's going to take about nine days, though the monolith is expected to fail in about six days. Worse, she says it'll start to turn white, meaning they won't be able to hide it for too long. She tells him their only hope is for him to gather enough people to try and fight off the Gastrea with the military until they can get a replacement in. But even then Rentaro is having problems recruiting enough people.
Godzilla Threshold: In episode 12, Miori hands Rentaro a bomb that's several times more powerful than the 500 pound bomb dropped on Aldebaran. However, she tells him said bomb has to be put inside of it for the bomb to work, and they can't just simply have it detonate outside of the Gastrea's body.
Rentaro has a lot of trouble getting enough people to help him and the government fend off against a Gastrea breach. Some don't trust the government, others still feel it'd be a hopeless fight since the Gastrea involved has been rumored to have destroyed multiple cities, and still others are jealous of Rentaro's sudden rise in ranks and popularity, and don't want to play second fiddle to him. Despite that however, he does manage to get enough people involved for the greater good of not letting Tokyo be overrun with Gastrea.
Rentaro calls Miori for backup in episode 12, since he needs her expertise in weaponry, as well as her family's resources to defeat Aldebaran. Kisara is not too happy with this for obvious reasons.
Rentaro in episode 10, when he's identifying bodies at a police station. He confirms that the bodies are of the Cursed Children he was trying to teach, who died in a bomb attack set off by some racist humans.
Averted twice in episode 12. The first is when Rentaro removes the sheet to confirm that Commander Gado, his superior during the Gastrea monolith breach, was in fact dead. The camera reveals the latter's face as Rentaro removes the bedsheet covering the body. The second occurs when Rentaro and Shoma find Midori's lifeless body limped next to a tree. Though only a little bit of blood coming from her head is seen, it should be obvious she committed suicide.
Grey and Gray Morality: Across from the Hiruko pair and some of the few unambiguously good characters like EnjuAihara and Seitenshi (as well as the Gastrea), a lot of characters portrayed in this series fall into this category. Rentaro is a good person at heart, but he's a Pragmatic Hero who is willing to use lethal force whenever necessary (although he's no means an Anti-Hero). Kisara Tendo is an Anti-Hero who desires for revenge and has a Pay Evil unto Evil approach. Kikunojyo Tendo is seen as a contradicting character, as he's extremely loyal to Seitenshi and treats his foster son, Rentaro, as his own actual son; yet he opposes her goals of implementing civil rights for the cursed children out of sheer hatred and is willing to resort to shady means of maintaining the status quo to the point of hiring the Hiruko pair to stir chaos as means of lowering the public opinion on the cursed children.
The politics involving the cursed children can easily fall into this. From the perspective of the Deprived Generation, the cursed children deserved to be hated in society and some of this may be justifiable since many of the survivors who lived through the war lost many relatives to the Gastrea and the sad eventual fate of the cursed children becoming Eldritch Abomination. On the other side, some people believe that the cursed children are human beings, should be treated equal, and are the key on defeating the Gastrea (even if granting such equal rights may involve costing the security of humanity). Kikunojyo holds the former point of view while Seitenshi and Rentaro holds the later.
Godwin's Law: Rentaro pulled this trope off when describing President Sougen of Osaka. To be more precise, Rentaro compares him to Hitler on how they both take advantages of tragedies and wars, reunite the people, and use the advantage as means of establishing a military supoerpower to Take Over the World.
Gone Horribly Right: There was an experiment to create human supersoldiers before the Cursed Children. This resulted in Hiruko.
Gory Discretion Shot: Happens to Kisara's brother in episode 13. His legs are sliced off at first, and Kisara leaves him, presumably content with the info he just gave her regarding his role in their parent's deaths. A moment later his glasses snap in half, and blood starts to ooze out of his face, and blood splatters against the walls. Rentaro goes back in to see what she did, though Kisara's brother's back is towards the camera during that scene.
The Ikuma/Senju pair is this. Shougen Ikuma uses a BFS to slash down enemies while Kayo Senju serves a backline sharpshooter support using a variety of guns and firearms.
Inverted with Rentaro and Enju. He largely focuses on guns, while she's the one that gets up close and personal. Also subverted that Rentaro is capable of close range combat when necessary.
He Is Not My Boyfriend: Kisara says this in episode 8 when the class of cursed children they were trying to teach asks her if she's dating Rentaro. Enju unsurprisingly is ecstatic about hearing that reply.
Heroic RROD: What happens if a cursed child overuses her superhuman abilties such as Healing Factor, Super Strength, and lightning reflexes? Their erosion rate increases and turn into the Gastrea quicker.
Hold the Line: In episode 4, Kayo says she'll stop the minor Gastrea so that Rentaro can focus on defeating Kagetane. She promises to run away if she's overwhelmed. Then it turns out she lied, and starts showing signs of turning into a Gastrea. That said, she does successfully kill all of the Gastrea in the local area, though at the cost of her life.
Hopeless War: Even after humanity's defeat against the Gastrea, they are still in a hopeless defensive war against the Gastrea.
The battle against Aldebaran's army was this, to put it into perspective, the first fight started with 8000 people versus 2000 Gastrea. Due to underestimating Aldebaran's intelligence, the 7000 government army got taken out and then the civil security lost 500 people, the enemy lost a number of 1400 but then replenished 2100 Gastreas. So after the first fight, the number difference is 2700 Gastrea versus 500 civil security.
In episode 12, with the defeat of Pleiades and its anti-aircraft weapons, the Japanese military drops bombs on the Gastrea. Rentaro also witnesses Aldebaran's head getting blown off by one of the bombs, only for it to grow right back.
During episode 13, Rentaro manages to plant the bomb inside Aldebaran. He then counts down, only for the bomb to malfunction and not go off.
Humans Are Bastards: The series looks into how humanity's constant fear of the Gastrea exposes us the dark and evil side of being human, particularly in regards to the cursed children where they are born with the said virus. The series also noted that humanity would rather fight each other to death for power over working together to defeat the Gastrea (this is highlighted by Rentaro about President Sougen of Osaka with his ambition to Take Over the World).
Shougen Ikuma is the huge guy while Kayo Senju is the tiny girl.
Arguably Rentaro and Enju as well, since she's much smaller than he is.
The Immune: The cursed children are born with the Gastrea virus in their own blood, yet still able to maintain their own human form and instead have superhuman abilities. Subverted, that the cursed children does have the potential to turn into the Gastrea.
Jump Scare: Used In-universe in episode 9, when Tina and Rentaro visit Sumire Muroto. They are unable to find her, but something moves in the foreground shot. Then her head falls on top of Tina's shoulder while also making a somewhat creepy face, prompting her to scream. It turns out she was really starving, and fortunately Rentaro had some food on him to give her.
Kick the Dog: The blind cursed child panhandling in episode 8. She hears what sounds like coins being tossed into her begging bowl, but a shot of it shows that it was just a Jerk Ass guy tossing a soda can pull tab in there. After witnessing that, Rentaro tells her to hide for a little while, and hands her a lot of cash.
Lighter and Softer: The manga, despite still being really dark, tone down some of the light novel's darker elements, themes, and characterization. For example, Shougen Ikuma is portrayed more of a Jerk with a Heart of Gold in the manga while the light novel portrayed him as a flatout Jerkass.
The anime can be this as well. Some of the scenes in the anime are drastically lighter and toned down than the light novel source. For example, the cursed children that Rentaro taught to were killed by a bomb in the anime. In the ilght novel, the said group of cursed children were beaten, raped, lynched, and murdered by an angry group of civilians that Rentaro protected instead.
Land of One City: Due to the societal collapse after the war against the Gastrea virus, many of the cities in Japan basically become city-states fending off against the Gastrea.
Love Triangle: Between Kisara, Rentaro, and Enju. Rentaro sees Enju as a little sister archetype though. Subverted that the author settles Kisara and Rentaro relationship as an Official Couple. Not to mention, Enju is more or less aware that the chances of being with Rentaro as a love interest is very minimal for good reasons.
Ludicrous Gibs: The Gastrea that Enju kicks in the first episode explodes after she does a charge into it.
Mass "Oh, Crap!": Several of the characters have this look on their face after they see a huge swarm of Gastrea approaching them at the beginning of episode 11.
Might Makes Right: This series kinda shows that in order to prove yourself morally better than the other, you need to resort to lethal force. So far, the guy who holds the strongest political power and influence in Tokyo happens be very racist towards the cursed children who is planning to eradicate them like vermin.
After Rentaro saves Kisara gets her to a hospital to give her a dialysis, she says he can hold her hand. He then slowly reaches for it, only for Kisara to then get groped by Enju who shows up right at that moment.
In episode 9, after he gives her a Declaration of Protection, he grabs her, and is seemingly about to give her a Love Confession. Then Enju, along with the other characters he recruited to help protect the breached monolith, interrupt them before he can say anything to her. Enju angrily accuses him of having groped her, which he denies.
Episode 6 has several moments that switch back and forth between serious action and romantic comedy.
Episode 10 has several moments that fluctuate between romantic comedy, and some rather dark serious tones involving character deaths, especially near the end of the episode.
Nice Girl: Seitenshi is a Reasonable Authority Figure who is fighting for equal rights for the cursed children. She also serves as a motherly figure to many of the protagonists in the series.
Enju Aihara. Despite being treated as trash by society, born as a cursed child, and have severe trust issues; Enju is one of the most kind-hearted and friendliest initiators that wants to protect her friends.
No Good Deed Goes Unpunished: Despite saving the camp from a flanking attack by leaving his position in episode1 1, Rentaro is ordered to go on a Suicide Mission to kill a Stage 4 Gastrea on his own. Kisara tries to stop him as she sees him leaving, but he dissuades her from running away together, stating that if they don't stop the Gastrea from invading Tokyo here there'd be no place to run to anyway.
No-Holds-Barred Beatdown: Rentaro is sometimes on the receiving end of one, such as against Kagetane in their first few encounters. He pays them back in kind however, when the opportunity arises.
Not So Different: Hiruko feels this way about Rentaro. He feels their existences both depend on fighting for others, which is why he wants to start another Gastrea War: To make sure people like them will always be needed.
A jealous Kisara breaks into the student council office in episode 6 after Miori pulls Rentaro in there to talk. She finds them a bit too close for her liking, and Miori walks off, telling him not to forget his promise about leaving Kisara's company to work for him, in exchange for her body. While that's not the deal they made, Miori wanted to taunt Kisara, who then gets mad at Rentaro despite him trying to explain the situation.
In episode 8, Tina spends a night with Rentaro and Enju. She's unable to sleep comfortably and ends up talking to Rentaro a bit, and ends up calling him "nii-san" or "big brother" because of how well he's been treating her. She then asks if she can sleep on his arm. The next morning Kisara arrives to pick Tina up, but she's no longer on his arm. Instead his blanket moves around a bit, and she says some rather suggestive sounding things that they did more than just talk. Kisara threatens to call the police while Enju has a shocked reaction. Tina then gets up and isn't wearing any pajama pants, further leading to the confusion.
Off with His Head!: Some Gastrea dogs suffer this fate in episode 11. A two headed one that was about to attack Rentaro returns to him shortly after it leaves, only to be missing one head, and the other falling off shortly afterwards.
In volume 3, A Gastrea manages to penetrate a hole in the Varanuim monolith wall, thus allowing other Gastrea parasites to invade Tokyo.
Rentaro has one at the end of episode 6, when he tries calling Enju back from attacking the assassin. While her phone is picked up, she doesn't answer it, leading him to believe the worst may have happened to her.
Oppressive States of America: The light novels mentioned many countries that treat cursed children much worse than Tokyo. United States happens to be one of them, as cursed children are hunted down and captured like wild animals, forced into slavery (usually either sold into sex slavery or to civil security companies), and used as experiments to unlock their superhuman abilities and implanting Varanium parts in their bodies.
Playing with Syringes: Tina Sprout mentions that the United States government forcefully made cursed children participate in many experiments ranging from forcing them to "unlock" their field ability to implanting Varanium parts into their bodies as mechanized Child Soldiers. Mind you that it is highly implied to be a very physically painful experiments on the cursed children, considering the fact that mixing Varanium and Gastrea isn't a a very good combination.
Police Brutality: This is highlighted a bit in the manga where a cursed child was taken by two policemen into a dark alley where they shot her to death (the anime shows them taking her to an abandoned apartment complex, who comment that their other shots didn't do her in). Prior to shooting her. the policemen blames her and the other cursed children that humanity cannot live in peace.
A recurring gag with the folks who work in Tendo Civil Security is that they are always poor no matter what. In the manga, Rentaro even bought two bags of bean sprouts simply because they were on sale and extremely cheap. Kisara even gets mad at him for that, because he didn't tell her about it, aside from not getting payment from the police for the Gastrea attack earlier.
In episode 6, Miori grabs Rentaro into the student council office, and Kisara starts banging on the door, demanding it be opened or else she'll break it down. Miori says she'll send the bill to repair the door to the latter's company, which stops her... for a short while anyway. She ends up breaking into the office after Rentaro is in there a bit too long for her liking, only to find out Miori is teasing him once again, which gets her mad at him.
Pyrrhic Victory: At the end of volume 4/episode 13, humanity manages to fend off the swarm of Gastrea invading Tokyo and repaired the Monolith wall. Unfortunately it came at a high cost, as 90% of Tokyo's military are killed, and out of a thousand Civil Securities that participated, only 20 manages to survive. It doesn't help to note that when the wall was damaged, many soldiers and civil securities decided to buy a plane ticket out of Tokyo, the military's lack of resources and manpower of fighting the swarm of Gastrea, other region's unwillingness to help out Tokyo, and the fact that there are two powerful Gastrea monsters that made the battle difficult.
Right Wing Militia Fanatic: The Five Wings Syndicate introduced in volume 6 is a secret uyoku dantai organization. Their goal is to reunite Japan under their iron fist and used genetically modified Gastrea for world domination. It is revealed that the main antagonist during the Fugitive Arch was secretly working for the said uyoku dantai organization in order to ruin Rentaro's life. It's also revealed that Sougen Saitake, the president of Osaka, is secretly working with the said organization.
Screw the Rules, I'm Doing What's Right: Rentaro leaves his position in episode 11 to attack some Gastrea that were released behind their camp and could flank their position. Despite being ordered not to go, he does anyway, and his group manages to fight off the flanking Gastrea. Unfortunately that didn't do much because the main Gastrea force still overwhelmed their position.
Show Within a Show: Tenchu Girls is a magical girl anime geared for young girls. Enju happens to be a huge fan of the series.
Single-Stroke Battle: Kisara versus her brother in episode 13. She deflects his spear, then runs him through. His legs are then lopped off, and he later dies from a delayed wound that shows up shortly after she leaves.
Sliding Scale of Idealism Versus Cynicism: Heavily on the cynical side. For starters, humanity lives in constant fear of the Gastrea and are forced to barricade themselves in Varanium monolith walls. Even with the walls there, Gastrea monsters can still pass through from time to time, not to mention that a Gastrea monster has even penetrated a hole in one of the walls in Tokyo. Because of the said fear, cursed children are treated as total trash with no rights and the situation gets and worse and worse them to the point that the government was even planning to strip them away from their citizenship and planning a genocide on them. The guy who holds the most political influence in Tokyo happens to be highly racist towards the cursed children who wants to eliminate them. Many characters are killed left and right throughout the series and there are virtually no hope for humanity to survive and defeat the Gastrea once in for all.
Spanner in the Works: One occurs at the end of episode 12, when the batteries needed by Rentaro's plans for attacking Aldebaran are being delivered by the Japanese military. Unfortunately Takuto and a couple of his men are seen deliberately dumping the batteries into a lake, mostly due to him wanting revenge against Rentaro for humiliating him back around episodes 6 and 7.
Spit Take: Rentaro does one in episode 7, after seeing Tina in their office. Kisara says she hired her partly so they can keep tabs on her, but also because she has nowhere else to go.
Square/Cube Law: This is discussed between Rentarou and Sumire in the first episode of the anime, although not referred to by name; the partly-insectoid Gastrea either subvert this law or does not obey it entirely.
Start My Own: Rentaro and Kisara start an impromptu school for the cursed children in episode 8 to help give them some semblance of a normal life. Unfortunately they have to hold the class in the ruins of a school, and the girls are more interested in Rentaro's romantic life.
Stop or I Will Shoot!: Rentaro uses this to disperse an angry crowd assaulting a blind Cursed child in episode 10, warning them that if they get any closer, he wasn't going to give them any more warning shots.
Suicide Mission: Rentaro is put on one in episode 11 for leaving his position when the camp was being attacked. He tries to justify his reasons, but the commander still feels he needs to be punished for disobeying orders.
Super Soldier: Before the Cursed Children, there was a project to create a series of these to fight the Gastrea; this is what resulted in Hiruko.
And when the light author doesn't kill someone off, he instead makes them suffer. Case in point, Enju Aihara is one of the most kind-hearted, loving, most optimistic, and friendliest lolis in the series who doesn't even hold a grudge against anyone. Yet, she receives the most suffering of all the characters in the series such having her status as a cursed child found out by her classmates, brutally beaten down by Tina, having her new friends of her kind that Rentaro taught to brutally killed off, and forcefully taken away by the IISO and forcefully paired up with a total stranger named "buddy killer," and her high corrosion rate. Her backstory even reveals how much suffering she has endured prior to becoming an Initiator, yet she maintains her happy and kind-hearted personality.
Trauma Conga Line: Oh boy, where to start. Nearly every character is placed in total utter hell throughout the series. Rentaro and Enju takes most of the pie.
More specifically for Rentaro in episode 10, he first finds the blind girl he helped back in episode 8 being assaulted by some angry humans due to one of the monoliths collapsing and potentially allowing Gastrea to infiltrate Tokyo. Fortunately he's able to save her from their assault. He then finds out the girls he was trying to teach at an impromptu school were killed in a bomb blast, laced with Varanium fragments to maximize the pain the girls felt with their Gastrea parts. He tries to avoid having Enju see them as well, but she unfortunately forces her way through, and criesquite a bit when she sees the bodies. Finally, when calling Kisara, the monolith starts to collapse earlier than anticipated, forcing them to deal with the Gastrea problem right away.
Also, the very purpose of Fugitive Arch. Rentaro got framed for the murder of his friend and had his licensed revoked, Kisara is forced to marry the main antagonist for the storyarch, Tina was sent to deathrow, and Enju forcefully taken away by IISO and forced to pair with a guy named "buddy killer" and implied that she suffered a lot of physical and emotional abuse from "buddy killer" during the time when Rentaro was a fugitive.
Ungrateful Bastard: Every heroic deed the protagonists do are never respected in return. Case in point, in volume 3, Rentaro and Kisara decided to start a school for cursed children to create hopes for their future. About a half volume later, the said group of cursed children they taught to are murdered and lynched by a group of civilians Rentaro protected. Though in the anime they are killed by a bomb set inside the class Rentaro and Kisara were teaching them. This makes him start wondering why they're even bothering to protect humans if they treat the Cursed Children this way.
Unobtainium: Varanuim, the Gastrea's Achilles' Heel, is extremely rare to find. The reason Japan has a large surplus of them is because they can only be found near volcanoes.
Villain Has a Point: As the series progresses and Rentaro sees more atrocities committed against cursed children, it's very hard not to believe that Kagetane was right about his beliefs that Humans Are Bastards that are not worth saving.
Rentaro is saved from some Gastrea dogs in episode 11 by Kagetane, the first major villain he fought back in episodes 1-4. The latter even provides him with bandages, antibiotics and food. But for obvious reasons, Rentaro is highly mistrustful of Kagetane's motives and has his gun pointed at the latter for quite some time even as he's patching himself up.
He's saved again by the duo in episode 12 after one of the Cursed Children fires a shot at him. Kagetane blocks the bullet from hitting Rentaro, while Kohina rushes to the girl, and says that if she attempts to move the former would simply cut her head off.
Weaponized Landmark: The Heaven's Ladder rail gun, which is a gigantic gun built on land and capable of shooting small objects at nearly the speed of light. It's put to good use in episode 4 when Rentaro needs it to destroy a Stage 5 Gastrea.
What the Cursed Children working with Initiators attempt to do, despite the Fantastic Racism and ostracization they face from regular people. Enju at times wonders if this is even worth it, due to the crappy way she and the other Cursed Children get treated despite risking their lives to kill Gastrea.
Played straight in episode 12 after Rentaro recruits Kagetane, who was the first major villain from the early episodes. For a variety of reasons, the other security teams don't trust him, but the greater threat of the Gastrea forces Rentaro to have them accept the help somewhat begrudgingly.
We Do the Impossible: The Tendo Security officers, specifically Rentaro. He's defeated major opponents that have threatened the Tokyo area and its people, and even manages to kill higher Stage Gastrea which even the Japanese military has extreme difficulty with.
What Measure Is a Non-Human?: Discussed heavily with the cursed children. Some of the characters have different interpretations of this. Seitenshi feels that they should be treated as equals with normal human beings. Kikunojyo is more cynical and see them as monsters and bugs that need to be eliminated. Dr. Sumire sees the cursed children as if they were messengers between humans and Gastrea.
When Kisara says she's joining Rentaro's team in protecting Tokyo in episode 9, he initially refuses to let her, citing her kidney problems. He then tries to say that he doesn't want her in danger, because he wouldn't know what to do if she got hurt or killed. Kisara then throws this right back at him, telling him she feels the same exact way about him every time he goes off to fight.
In episode 12, after Rentaro is forced to take command of the surviving Security officers, one of them states they should all just abandon Tokyo and run away. He then promptly pulls out a katana, and stabs the guy in the shoulder with it for insubordination. One of the Cursed Children fires a shot at him in retaliation, only for Kagetane to stop it. Kisara calls him out on it, saying the others are going to loathe him if he keeps this up. However, Rentaro says he was being a Jerk Ass because he realized how bad the morale was, and hoped to give the security teams someone to hate rather than have them focus on running away in a seemingly lost cause fighting the Gastrea.
Rentaro does this to Kisara in episode 13 after she kills her brother for his part in their parents getting killed by the Gastrea. She tries to justify the killing, stating that Rentaro doesn't have it in him to kill people, so she'll do it instead. However, he fears that he may end up having to fight her someday if she keeps this up.
Wham Episode: Episode 10. Rentaro and Enju arrive at the school just to find that all the other cursed children were killed by a bomb and they have little time to mourn them when Monolith 32 collapses one day earlier than expected.
In episode 12, Rentaro and Kagetane catch the Gastrea and Pleiades, one of the Stage 4 Gastrea that was involved in the current Gastrea invasion. Rentaro had planned to use some plastic explosives on it, but lost it when he fell into the river in the previous episode. Both of them then decide to just rush and punch it really hard with their Varanium limbs, which manages to kill it.
He tries this again in episode 13 against Aldebaran, but unfortunately it releases a chemical which corrodes and destroys Rentaro's varanium leg. He still tries to approach it anyway by slowly crawling towards it, but Shoma rescues him from almost certain death. Shoma then does what he suspects Rentaro was attempting to do, although he dies in the process due to being caught in the explosion inside Aldebaran as it goes off after he punches it.
Averted with Kagetane. He does have a gun that he uses regularly, as well as some other abilities to protect him, such as a forcefield that can block bullets from hitting him, as many people found out in episode 2. The only reason he didn't outright kill Rentaro was because he found him interesting and tries to have them work together.
Played straight with the assassin Tina Sprout in episode 6. While she clearly has the upper hand, she hesitates to shoot, causing Kisara to wonder if she's afraid to kill someone, at least up close. The assassin then tosses her gun away, and just attempts to choke her to death. Fortunately Rentaro arrives in time to save her.
Happens again in episode 7, this time to Rentaro after he's easily curbstomped by the sniper. His flashbang takes a few seconds to activate, but this blinds and disorients Tina enough to give him an opening to defeat her.
Rentaro nearly suffers from this himself in episode 12, after a Cursed Child fires at him in retaliation for him stabbing a security officer for insubordination.
Wife Husbandry: The cursed children in episode 8 ask Rentaro if he's doing this with Enju. He vehemently denies it. But Enju is given a small Hope Spot when Kisara says she's not dating him or planning to marry him.
Episode 10 goes further, with several of Rentaro's students, including Enju and Tina, openly expressing their will to marry him.
World of Action Girls: Due to the sheer amount of named female characters (some of which are cursed children, who are Always Female), almost all of which can fight competently. Only a few avert this, such as Seitenshi.
Worthy Opponent: Kagetane sees Rentaro as this and hopes to persuade him to join his side, which is why he spares his life on many occasions and in some cases even helps him.
X Meets Y: Zettai Karen Children meets Elfen Lied. Tyke Bomb with a handler to supervise/watch out for them, a bad guy who wants to corrupt the heroes and have them work together, combined with girls who are born with a disease that gives them special abilities, but at the same time causes humans to ostracize them.
You Are in Command Now: After Commander Gado is killed in episode 12, Rentaro, as the next highest ranking officer, is forced to take command of the surviving Security teams.
Your Head Asplode: Aldebaran suffers this in episode 12 when a 500 pound bomb hits the creature's head. Unfortunately due to its Healing Factor, Rentaro watches in horror as it simply regrows its lost head.
0% Approval Rating: The ultimate goal that Kikunojou wants to do to the cursed children when he hired the Hiruko pair.