Alice Fuji does not have a fun life. She's spent the last few years being tormented and abused by her drunken uncle, whilst her unusual mental disorder and dearth of social skills have led to poor grades and a complete lack of friends at school. Then a mysterious assassin kills her uncle, press-gangs her as his apprentice, and subjects her to Training from Hell for a few weeks before trying to kill her when her recruitment application falls through. Now she's got an ever-increasing price on her head as she fends off one murderous, arthropod-themed lunatic after another, and the only allies she can turn to are the slightly less murderous arthropod-themed lunatics.A manga written by Shinya Murata since 2009, Arachnid provides an unusual take on the standard shonen Fighting Series, with an interestingly deranged cast and a wide variety of exotic fighting styles. It also has a spinoff story named Caterpillar, which focuses on an assassin named Imomushi who has her own troubles within the Organization some time before Alice became involved.
Arachnid contains examples of:
Academy of Adventure: A polite way to describe Alice's school. A less polite (though somewhat more accurate) description would be 'death-trap crawling with murderous psychos'.
Action Girl: Alice and virtually any other female assassin.
Aerith and Bob: Most of the characters have insect codenames rather than actual names, while normally-named Alice refuses to give up her identity to the Organization.
Animal Motifs: ...or rather, an insect motif, each for every assassin. Alice, however, gets a handful of different spider species motifs for the sakeof versatility.
Attempted Rape: Alice from her uncle in the very first chapter, and then Oki from Hibiki's thugs in Chapter 12. Gets worse later, when the main villain brainwashes students into raping any others they can find.
Big Bad: "Army Ant" Sara Kurokawa claims she's the boss of the Organization.
Blade Below the Shoulder: Dinoponera has extendable needles inside her gauntlets, which have the immensely painful effect of her namesake's sting. Bullet Ant and Suzume Bachi also use this weapon type.
Blade on a Stick: Kabuto Beetle wields a halberd with enough strength to shove people far away and make craters on the ground.
Blade Run: Dinoponera sits on Kabuto Beetle's halberd when Kabuto first tries to attack her, then hangs on it to avoid being smashed into the ceiling. Later she also walks on the halberd's pole, too.
Bottomless Magazines: There's no concern in-story about whether there is a limit on the thread from Alice's Kumoito.
Brainwashed and Crazy: At one point Oki is controlled by Digger Wasp, who gives her a dominatrix outfit and has her believe he is Alice. Oki doesn't seem to notice how unusual "Alice"'s orders (such as torturing her friend Yori) are and gladly follows them while not actually being any crazier than she already is. Meanwhile, Sara leads and spreads zombie-like mindless students around for them to overpower and rape her enemies.
The Bully: Yoriko is terribly cruel to Alice in the early chapters, to the point Alice considers killing her, but after the first encounter with Sasori, Yori has to keep Alice with her for protection and the two begin to get along.
Carnival of Killers: Alice has a price on her head which increases as the assassins after her kill each other.
Catch Phrase: When her life's in danger, Alice says she can only kill to survive.
Damsel in Distress: Early on, Oki fakes kidnapping Yoriko to bait Alice. But later Yori is captured by the Sand and Digger Wasps to be tortured by a brainwashed Oki. She tries to stay out of Alice's fight against Dinoponera, but Dinoponera jumps behind her anyway to get a reaction from Alice. When Alice reunites with her later, Yori is attacked by Sasori.
Deer in the Headlights: Alice is shocked when Kumo tries to kill her at the beginning, but then she jumps to chomp his neck off. She later becomes feared for being able to avoid being completely frozen even in such dire situations.
Decoy Protagonist: You know that cool looking assassin that keeps Alice in his house? Alice kills him at the end of the first volume.
Disability Superpower: Alice's "Congenital Excessive Concentration", which causes her to single-mindedly concentrate on the most inconvenient things. With training, though, it allows her to enter a kind of Hyper Awareness state and formulate battle strategies in seconds, and serves as arguably her greatest weapon.
Hair Antennae: Oki, as part of her cockroach theme. They even move while she's detecting movements around her.
Hammerspace: Kabuto Beetle hides her Kabuto Horn halberd folded in half under her shirt, but it's still far too big for it to make much sense. Then there's Geji who hits Oki with a heavy filled sock that she was still wearing on the previous page.
Hard Work Hardly Works: Having fought alone in wars during her whole life, Dinoponera expected to find a kindred spirit in Alice, but becomes enraged upon finding out she only recently became an assassin and yet mastered her ability in a couple of weeks.
Despite her best efforts, Dinoponera still gets tangled up and forced to stab her own leg.
Hyper Awareness: Alice, Oki, Sasori and Dinoponera have their own ways of feeling the environment around them and instantly countering any threats.
I Just Want to Have Friends: Alice has been lonely and shunned by people, Oki doesn't seem completely ok with being alone and hated, and Dinoponera, who also grew alone, would like to meet someone she can symphatize with.
Impaled with Extreme Prejudice: Dinoponera repeatedly impales people not necessarily to kill, but to have fun watching them scream because of her stings' "24 to 48 hours of great pain" venom. Alice gets stabbed all over her arms, legs and butt because Dinoponera was that much pissed off at the time.
I'm Okay: Only five "insects" are dead by the 40th chapter, a few of the recurring characters even say so after getting back up from the ground. Even Kumo is implied to have faked his death.
Inadvertent Entrance Cue: One scene has Imomushi stating she didn't necessarily come to Alice's school to fight her but is interested on the reward on her head. Cue awkward silence as Alice enters the room.
Insect Queen: Sara, who is Army Ant-themed, can dominate weak-willed people and is followed around by brainwashed minions.
Irony: The two times Oki ordered an opponent to be her slave, she became enslaved instead.
It's Personal: Hibiki hates Alice because she killed Kumo. He doesn't realize Kumo forced her to do that.
It Runs on Nonsensoleum: Other than Kabuto and her implanted armor, most of the characters don't seem enhanced. But even when their tricks are just plain supernatural, they're able to do them because they somehow fit in their insect motif, without any further explanations other than "they did special training".
Justice Will Prevail: Having watched a little too much tokusatsu shows, Hibiki claims to fight for justice and love, and regards his opponents as evil.
Make Me Wanna Shout: While bored from fighting Hibiki, Dinoponera suddenly stuns everyone in the corridor with a loud scream. She does it again later to escape after being defeated by Alice, though Kabuto isn't affected and almost crushes her.
Missing Mom: Alice's mother, who was Driven to Suicide after too much stress. Dinoponera's mother died protecting her from being crushed by falling rubble. Neither Alice's or Dinoponera's fathers are seen through the story. And the assassins who served as father figures for them are both dead.
Near Death Experience: This trope tends to trigger the killer in Alice, while Dinoponera is shown on a flashback awakening her own concentration technique to survive an ambush, at a very young age.
No Sell: Dinoponera seems immune to blunt damage. She gets blown away by a kick to the face and then just stands up with a smirk. After this she gets stomped countless times and just gets a bit embarrassed, without damage even to her clothes.
People Puppets: Alice can trap people with her threads to force them to move against their will. And if she happens to be paralysed, she can pull herself around too. She calls it "Marionette del Ragno" in chapter 49.
Posthumous Character: Kumo's commmentary on some characters' abilities is remembered by those who knew him.
Strong Ants: Sara (Army Ant) and Dinoponera (Giant Needle Ant and Dinoponera) are ant-themed. The first seems helpless in battle and depends on her minions. The later is shown to be greatly strong and resistent.
Un-Person: The Organization owns all records of their members' existances and is able to erase those if they die. Alice refuses to join them to avoid becoming this.
Use Your Head: Imomushi's main attack is to catapult herself head-first on enemies.
Webcomic Time: About thirty chapters all happened in one afternoon. Still going.
The Worf Effect: Oki claims she's the fastest among the assassins, yet gets easily beaten when someone turns out to be more danguerous than her. Kabuto Beetle is shown to be one of the strongest insects around before Dinoponera beats her up. Dinoponera is unmatched for a while until Alice surpasses her, causing Dinoponera to flee and be cornered and defeated by Sasori as well.