"Hey, you listenin' to me?! Don't work yourself to death! If it hurts too much, get yourself the hell elsewhere! Live your life the way you want!"
The war between the humans and the Demon Queen Echidna has come to an end with Echidna's army decimated by the Hero Leo Demonhart. Instead of praise and glory for his efforts, though, Leo is met with suspicion over his inhuman strength to the point of becoming a drifting outcast. Faced with no home and no future, Leo decides to... sign up for the Demon Queen's army?
I'm Quitting Heroing: Next Gig Is at the Demon Queen's Castle, or Yuusha, Yamemasu, is a fantasy light novel series that ran online from January to February 2017 and in print from December 2017 to October 2018. It received a manga adaptation starting in 2018 and an anime adaptation airing in the Spring 2022 season.
I'm Quitting Heroing provides examples of:
- Adaptational Nice Guy: The king, in the anime, at least thanks Leo for all he has done and assures him that he still trusts him. In the manga, the kings tells him the same, but Leo notices that there was fear in his eyes, meaning that he was just saying this to appease Leo.
- After the End: Surprisingly, the series takes place in a post-modern world as shown by several destroyed skyscrapers and a few destroyed cars. Something must've happened to put the world into the medieval era.
- Always Someone Better: Leo is the Someone to pretty much the rest of the main cast. Not only is he far more powerful than both the Demon Generals and the Demon Queen herself, he, being far older than them, also has more experience than most individuals. This gets deconstructed as Echidna eventually starts to consider the possibility that Leo might be better suited to be Demon King than her.
- Becoming the Mask: After Leo's true Suicide by Cop plans are revealed, Echidna and the Four Generals ultimately convince Leo to keep helping them instead, and Leo finds a new purpose in protecting humanity by making the Demon World a better place as Echidna dreams, thus making it so demons will no longer invade Earth for resources.
- Berserk Button: For the first arc Echidna completely loses it any time Leo is mentioned, unwilling to even consider letting him join the Demon Army after how he humiliated her and her underlings as The Hero, despite Echidna believing in Equal-Opportunity Evil and it being obvious how much someone as powerful as Leo could help their cause.
- Best Her to Bed Her: After Leo defeated Lili, he found out that her tribe's custom is to marry someone of the opposite sex who defeats them in combat.
- Big Good: To the humans Echidna is the leader of the demons threatening their very existence. To the demons however, she's a benevolent ruler who sought to give them a better life. Since she becomes Leo's boss, she fulfills the role of Big Good rather than Big Bad.
- Blood Knight: The only thing Edwald cares about is a good fight with a strong opponent, considering it more important than the possibility of becoming a ruler.
- Bullying a Dragon: After he defeated the demon queen, people feared Leo's strength and shunned him for it, to the extent of sending assassins after him.
- A Child Shall Lead Them: Lili is considered 1 of the 4 Demon Generals in charge of logistics despite being essentially a child who still submits reports in crayon drawings and gets distracted by playing while undertaking important missions.
- Chivalrous Pervert: Leo to Shutina. He's fond of making teasing advances towards her, but willing to help her out whenever he can.
- Crippling Overspecialization: Shutina, Melnes, and Edwald are more powerful than Leo in their area of combat expertise, but have no defense against attacks outside those specializations. For example, all it took for Leo to defeat Shutina back in his heroing days was to nullify all magic, leaving Shutina to harmlessly try to whack him with her staff before quickly exhausting herself and having no defense against his inevitable counter-attacks.
- Cutting the Knot: Leo attempts to teach Lili the value of teamwork by poisoning himself with a poison he can easily cure himself. This is so that Leo can trick Lili into going through several obstacles he assumes she won't be able to pass in order to obtain the antidote. Lili repeatedly frustrates Leo by simply brute forcing her way through nearly all the obstacles Leo had set up for her by herself.
- Department of Redundancy Department: Leo's incognito name is Black Knight Onyx. Onyx, being another shade of black, makes his name out to be Black Knight Black.
- Desperately Looking for a Purpose in Life: Leo's actual motivation. He was created as a Human Weapon to protect humanity from threats, and yet the world has become increasingly peaceful thanks to his centuries of effort, to the point humanity regularly no longer needs him. Leo so desperately wants a purpose, he was even considering making his own threats to humanity that he could then save them from. After realizing how screwed up this line of thinking was, Leo went to the Demon Army not for a job but to find out if they could be trusted with the Philosopher Stone that powers him, and if so make them kill him, before his desire for purpose consumes him.
- Didn't Think This Through: After defeating the Demon Queen's Army singlehandedly, the human kingdom seriously thought that assassins, of all things could kill Leo. Even Leo himself points out their stupidity.
- Dude, Where's My Respect?: Leo stops the Demon Army almost singlehandedly, yet everyone treats him with suspicion and fear. They are even willing to send assassins after him, and when that fails the king exiles him.
- Earth All Along: The apparent fantasy world is actually Earth, regressed into a Medieval Stasis after centuries of war with the alien invaders from another dimension known as demons.
- Earthy Barefoot Character: Lili is a barefooter, appropriately for an animalistic character in barbarian attire.
- Easy Amnesia: Leo and Lili originally met when Lili forgot who she was and traveled with him for a time. After falling she regained her memory and attacked him, only to be instantly defeated.
- Everyone Has Standards: After hearing the story of how Leo was exiled, the generals can't help but feel sympathy for him.
- The Exile: Due to his strength and the people of the country rejecting him as a potential demon lord, the king of the country Leo fought for decides to banish him. He's threatened with this by Shutina if he doesn't show results in his probationary period when he joins the Demon Army.
- Explain, Explain... Oh, Crap!: When Leo starts to look at the current state of the demon army, he goes over what each of the four generals are tasked with. He then comes across logistics, which is a major issue to any army, only to discover it's Lili that's been tasked with it. When he brings this up, the other generals nerviously look away, causing Leo to realize that they are so strained that she was the only one they could get to cover it.
- The Four Gods: The four main generals in Echidna's army are referred as such.
- Hard-Drinking Party Girl: Echidna becomes this when she hosts a private drinking party for Leo (in his Onyx disguise), especially after Leo tries to get out of the party by repeatedly refilling her glass and getting her black-out drunk. Unfortunately, several empty bottles of wines, liquors, and spirits later, Echidna is both still conscious and lucid enough to declare that the party will continue till dawn the next day before drinking straight from another wine bottle.
- Has a Type: Leo loves voluptuous women with mature personalities. Shutina and pre-defeat Echidna definitely fit the bill, causing him to regularly tease and hit on them. Lili, not so much.
- Humans Are the Real Monsters: When you look at everything the humans did to poor Leo, despite everything he did to save them (even the king exiled him), compared to how the "monsters" treat him, you can't help but think of this trope.
- Human-Demon Hybrid: What Leo and all the Demonharts actually are, Designer Babies made from combinations of human and demon DNA and empowered with a crystallization of demonic energy known as the "Philosopher Stone" to give them incredible abilities.
- I Cannot Self-Terminate: Leo was designed to "protect humans", but after they no longer needed him, he became suicidally depressed after losing his one purpose. So he joined the Demon Army to see if they were worthy of his Philosopher's Stone Heart, and that they could kill him before he destroyed the world just to make them need him again.
- I Have Boobs, You Must Obey!: Shutina pulls this on Leo, using a combination of special tea and incense to lower his inhibitions, and the succubi's most powerful charm spell, to compel him into aiding her to clear a dungeon he'd rather avoid. Shutina offhandedly mentions this tactic is only used by a succubus to enthrall their One True Love. Neither catch the implication.
- Innocently Insensitive: Leo makes very good points that his superior skills are sorely needed for Echidna and her army. Unfortunately, he brings up their previous humiliating defeats as examples which obviously just makes them, mainly Echidna not to recruit him.
- I Thought Everyone Could Do That: Edwalds' flaw. He believes that anyone can get as strong as him through hard training, ignoring that his race is naturally stronger than others.
- Jerkass Has a Point: The whole of humanity feared Leo after he singlehandedly saved them from the Demon Army out of paranoia that Leo might one day turn on humanity. As it turns out, Leo very nearly did exactly that out of his desperation for a purpose drove him to recreate the Demonhart series in order to manufacture threats to humanity only to destroy them before completion upon realizing what he was about to do. They were more right to fear that possibility than they knew.
- Madness Mantra: Leo and the other Demonhart series had one command constantly drilled into their brains, "Protect humanity from evil".
- Magikarp Power: Leo was initially the weakest of the Demonhart series, built around the mundane concept of infinite growth along with Power Copying. However centuries of fighting and training has allowed him to obtain a monstrous amount of skills and strength; including the abilities of the other Demonharts after they had passed on, ultimately making him the most powerful Demonhart and possibly the most powerful being alive in the present.
- Master of Disguise: Leo has mastered the "Metamorphise" magic and can use it to easily change his appearance and clothing at will. In fact, even his current appearance is not his original one.
- Moment of Weakness: At some point before the demon invasion, Leo, driven mad during times of peace, tried to recreate the Demonhart series to this time constantly attack humanity to give his life purpose. It was the demon invasion, which renewed his purpose, that he realized how far he has fallen. He destroyed the new series and then planned on dying to someone he could trust his Philosopher's Stone heart to.
- Never Gets Drunk: Echidna can get drunk, but she has the ability to instantly sober up if she needs to.
- No Good Deed Goes Unpunished: Leo saves humanity from the demon army. However, rather than welcoming him as a hero, the people regard him as a threat, and the king eventually exiles him.
- The Nose Knows: Lili has a very keen sense of smell, to where she quickly realized Black Knight Onyx was Leo, despite in full body armor.
- Pint-Sized Powerhouse: Lili may be the size of a little girl, but she became the Beast General and one of Echidna's top commanders for a reason.
- One-Man Army: Leo, to the point that he considered the other members in his party burdens. He has in fact wiped out multiple invading demon armies all by himself, going all the way back to the very first invasion over 3000 years ago.
- Older Than They Look: Leo is actually centuries old and older than pretty much all the other characters in the story, a Human Weapon made in the very first age humanity made contact with demons, where he was created to defend humanity from demons.
- Reasonable Authority Figure: The Demon Queen Echidna is this in spades. All she does is for the sake of her subjects. She also extends this to humans, as she tries her best to avoid pointless death.
- The Reveal: Leo is not just a generic hero of a Standard Fantasy Setting who defeated the Demon King Echidna and then went to join her Demon Army after the humans kicked him out in fear of his power. The fantasy world is in fact an After the End Earth, and Leo its Eternal Hero, the last surviving member of a group of Human Weapon Designer Babies known as the Demonharts, who has been single-handedly wiping out invading Demon armies for centuries. Further, Leo doesn't need a job, but rather is investigating what Echidna wants a Philospher's Stone for, since it is in fact what powers him. If he thinks it's a good cause, he wants Echidna and her friends to kill him, as due to humanity needing him less and less, he has considered Fake Ultimate Hero plans to create his own threats to humanity that he will then be able to save them from.
- Self-Fulfilling Prophecy: After Leo defeated the Demon Army, the humans suspected since he was so powerful he would one day turn on them. Therefore they only looked at him with fear and suspicion until it got so bad that the King exiled him. Because of how he was treated, he joins the Demon Army to get his revenge.
- Skyward Scream: What Echidna does after defeating Leo.
- Stalker with a Crush: Canaan for her Sexy Mentor Shutina, complete with a Stalker Shrine covered in pictures, dolls and "observation logs".
- Story-Breaker Power: Deconstructed. Leo's overwhelming strength and abilities ultimately leave him feared, ostracized, and hated by the other humans after defeating the devil's queen's army.
- Surprisingly Realistic Outcome: Upon defeating the Devil Queen's army all on his own, Leo is met with nothing but fear and contempt from the other humans, who come to view him as no different from the very demons he just saved them from, instead of the usual hero's welcome that exists in other stories due to his inhuman strength and abilities. At the end of the day, humans will always fear that which they don't understand, especially if it's something that's far more powerful than they are. Even the king (Who was at the very least grateful to Leo) eventually exiles Leo from the kingdom just to appease the populace.
- Squishy Wizard: Shutina knows every magical art that has ever existed, but project an Anti-Magic field (like Leo did), and she's reduced to merely hitting her opponent with her staff, ineffectively against Leo completely, not to mention looking quite hilarious while doing so.
- Then Let Me Be Evil: Leo gets sick and tired of humanity being afraid of him, spreading rumours that he is going to use his unnatural power to take over, and trying to have him assassinated. Eventually he decides if they're all going to view him as a monster just like the demons, his fight to protect them has no meaning and he might as well become their enemy like they fear by joining the demon army.
- Too Dumb to Live: Paranoia drives several people to send assassins after Leo, who just defeated the Demon Queen Echidna and her army by himself. Leo himself lampshades their idiocy.
- Trauma Button: Brutal Bonus Level dungeons designed by Canaan are these for Leo and everyone else forced to experience them, due to her expertise at Solve the Soup Cans puzzles.
- Tsundere: Echidna is a Sweet type. She is, at first at least, hostile towards Leo, because he ruined her plans to acquire the Philosopher Stone, but aside from that she's a very approachable and kind individual that only seeks what's better for her subjects and truly wants a world where humans and demons can live together in peace. She even admits that she doesn't truly resent Leo, as he was simply protecting humanity from an invading army. She quickly warms up to Leo after they spend some time together.
- Unexpected Virgin: Shutina is a high ranking and powerful succubus, but has zero experience with men. Leo's flirting tends to embarrass her.
- Universally Beloved Leader: The Demon Queen Echidna is adored by all her subjects. Even after her being defeated by Leo, thus ruining the chance of the demons taking over the world, neither of her subjects demand for her to step down and all keep serving under her. Leo himself aknowledges that is one thing that Echidna surpasses him in terms of.
- Vague Age: Lili looks and acts like a hyperactive child, but the fact she is one of the main four generals suggest she is Older Than She Looks.
- Voluntary Shapeshifting: Lili has the ability to turn into a legendary Fenrir at will.
- Well-Intentioned Extremist: Echidna sought to invade the human lands in order to acquire the Philosopher Stone, which would allow her to create a new Demon World. This is due to the fact that the current Demon World is a wasteland. The fact that she wants to do this with as less bloodshed as possible and that she doesn't despise humans puts the Extremist part up to question.
- Western Zodiac: The Demonhart series were each given a name based on this.
