"Don't cry. If you cry, you'll lose."
The Killer of the title. Ichi is a 22-year-old man-child who lives by himself in a big house. A childlike loner, he gets bullied around by almost everyone he meets and reacts by apologizing. He spends his days working at a metal factory and going to the red-light district. At night, he is a deadly assassin. Whenever pushed to the brink emotionally and past the Despair Event Horizon, he becomes a monster capable of tearing men to shreds. At first, he only kills when his mysterious guardian Jijii orders him to.
- Absurdly Sharp Blade: His boot razors, which he makes in the welding factory where he works.
- Almighty Janitor: Has unbelievable lower body strength and has spent quite some time practicing karate, yet he remains a white belt; this of course by his own choice due low self-esteem, Ichi thinks he doesn't deserve anything better than a beginner belt.
- Anti-Hero: Well, sort of.
- Axe Crazy: Whenever he starts to cry, run as far as you can.
- Berserker Tears: Ichi cries when he's in his killing trance, since he both hates his own repressed ultra-violent tendencies and is simultaneously fueled by rage at the bullies who made his childhood a living hell.
- Character Development: At the very end of the manga, although we don't get to see much of it, Ichi seems to have become more sociable and able to speak with girls normally, as seen in the hostess club; but he maintains his freaky smile and killer impulse.
- Dark and Troubled Past
- Despair Event Horizon: He is pushed past it whenever someone attacks him in a way reminiscent of the bullies in his childhood.
- I Know Mortal Kombat
- Loners Are Freaks
- Morality Pet: His friendship with Kaneko's son Takeshi, who views him as "my wimpy big brother". Also Ichi's earlier friendship with the bullied kid, where he teaches the kid how to fight off the bullies.
- My God, What Have I Done?: His reaction after killing his girlfriend-prostitute by accident.
- Pet the Dog: Consoling the poor abused prostitute, and even giving her money so she can have her nose fixed. They even have a romantic moment and he promises to kill her abusive pimp for her...that ends badly.
- Nightmare Fuel Station Attendant: With puppy eyes and a sweet smile: "No. I didn't want to have sex. I wanted to rape her."
- Orgasmic Combat: Literally. The only way he can achieve an orgasm is through beating and killing others.
- Psychopathic Manchild: Ichi, you ARE this trope.
- The Un-Smile: His creepy nervous "smile".
- Tyke Bomb
- Unstoppable Rage: Whenever he goes into his killing trance.
- Woobie, Destroyer of Worlds: It's hard not to feel bad for this guy, especially since he knows he's insane and wants to be normal.
"Moral code, what's that?"Arguably the Villain Protagonist of this story. A Yakuza mobster who is equal parts sadist and masochist, he loves both receiving pain and dishing it out. He cuts, burns and pierces his body, and has twin friends who engage in S&M with him. His story begins when he finds out his boss and lover, Anjo, has gone missing. Kakihara is intrigued and goes in pursuit of Anjo's killer, but along the way takes over the gang. He eventually decides that Anjo's killer - Ichi - is the ultimate sadist he's been searching for.
- All Love Is Unrequited: Towards Ichi.
- Bad Ass
- Berserk Button-Belittle his former boss or the Anjou Clan at your own risk.
- Big Bad: While he is the main point-of-view character in the manga, Kakihara is also the leader of the Yakuza that Ichi and Jijii are trying to take down, making him the leading antagonistic force.
- Cold-Blooded Torture: Oh, God. Since he's an extreme masochist, he is an expert at the human body and its physical limits, and applies this knowledge to his victims. His specialty is genital mutilation and keeping his victim conscious as long as possible.
- Combat Sadomasochist: He's even the page image.
- Deadpan Snarker
- Dragon Ascendant: He was once a high ranked enforcer until his boss was killed and spends the manga taking over his gang and trying to get revenge.
- Foe Yay: With Ichi.
- Glasgow Grin: A self-inflicted one.
- Actually Saburo did it, back when they were in their previous gang, and the fallout from it scared him and his brother so badly that they never wanted to get on his bad side again.
- Good Scars, Evil Scars: He has a horizontal scar running across his cheeks and nose, a horizontal scar across his forehead, and a vertical scar that connects both over his left eye. In addition to a Glasgow Grin held together by piercings at the edge of his lips.
- In Love with Your Carnage: He feels this way when seeing Ichi's killings.
- Nightmare Fetishist-Kakihara's hobbies are torturing people and being tortured.
- Orgasmic Combat
- Sex Is Violence: "There's no love in your punches!"
- Too Kinky to Torture
JijiiThe self-appointed superhero of Shinjuku. He's an old police officer and Ichi's guardian, who has turned the man-child into an unstoppable killer through Mind Rape and brainwashing. Jijii is a mysterious old man (Jijii means "old guy") who has dedicated his entire life to balance out the good and evil in the city. Well, rather, the greater evil and the lesser evil.(Note, these tropes only apply for the movie.)
- Affably Evil
- Badass Grandpa: He always dresses very plainly so it's not visible, but he's RIPPED.
- The Chessmaster
- Chronic Backstabbing Disorder: He betrayed almost every member of his own little gang.
- Clark Kent Outfit
- Cowboy Cop: He's a former cop whose goal is to eradicate the Yakuza from the city.
- Gambit Roulette: Oh, so very much.
- Magnificent Bastard: Every main character except Ichi ends up dead because of Jijii.
- Mind Rape: What he did to Ichi. No one deserves to have these horrendous "memories" implanted in them.
- Mr. Exposition
- Old Master
- Well-Intentioned Extremist: He's willing to go to its uttermost extreme.
- Younger Than He Looks: He looks like a geezer but he's actually on his late 30s... supposedly. This is thanks to Magic Plastic Surgery.
- Hitman with a Heart
- Morality Pet: Strangely enough, Ichi is this to Kaneko. His company brings out Ichi's best sides, and Ichi views him as a cool big brother.
- Only Sane Man: When there's only him left in the gang, with Kakihara and Saburo.
- Professional Killer: A low-ranking hitman.
- Token Good Teammate
- Dumb Blonde: Appears to be this initially in the manga. She isn't.
- Evil Is Sexy
- Manipulative Bitch
- The Mole: Works for Jijii.
- Unwitting Pawn: In the end.
- Chekhov's Gunman
- Tyke Bomb: He ends up as Jijii's new assassin.
- When You Coming Home, Dad?: Used in the most tragic way.
- Woobie, Destroyer of Worlds: After his father dies and Jijii takes him in.
Jiro and Saburo
- Badass in a Nice Suit: In shiny white business suits, no less.
- Co-Dragons: They are Kakihara's most trusted enforcers and before Ichi can finally face Kakihara he has to kill both of them.
- Creepy Twins
- For the Evulz
- Psycho for Hire
- Rape Is a Special Kind of Evil: They rape their way through the series. Almost every woman they're alone with is raped and brutalized by them.
- Theme Naming: Together with their late brother, Ichiro. Ichiro, Jiro and Saburo means "First Son", "Second Son" and "Third Son"
- There Can Only Be One
- Twin Banter: It starts out as normal sibling banter, and often devolves into a furious competition that frequently ends up with those around the twins being harmed.
- Twin Telepathy: One can detect when the other has been killed. They used to be triplets.