Nana is a young boy who [[AmnesiacHero suffers from extreme amnesia]] and thus, cannot remember anything from his life beyond recently. Even so, he still enjoys a peaceful life. However, after the town he's staying in is attacked by TheEmpire and he witnesses the deaths of three children, he takes it upon himself to stop war and protect the people he cares about.

At first, despite his incredible strength, it seems that he won't be able to do anything, but he is saved when the freedom fighters of the organization Tripeace get involved. They proclaim their goals to rid the world of all war, even if it means getting involved in armed combat themselves. Nana, amazed at Tripeace's heroic goals and the incredible strength of its members, decides that in order to achieve his dream of creating a world without war, he'll join Tripeace and fight with them!

Through an odd chain of events that includes Nana [[WholesomeCrossdresser cross dressing]] and pretending to be a member of Tripeace, he's eventually allowed to join their group. Now follow Nana and friends as they work to end conflict and bring peace to their world in the name of [[RuleOfThree peace, love, and the third law!]]

!!''Tripeace'' provides examples of:

* AffablyEvil: A lot of the villains are friendly and polite, or at least act like it.
* AmnesiacHero: Nana. [[spoiler: Currently reversed: he remembers being the founder of Ares/Hades, but not his life in Tripeace or why he wears a scrap of red ribbon that he can't take off.]]
* AttractiveBentGender: Nanako, who is Nana dressed as a girl. Shiro prefers her.
* AwfulTruth: The name of the chapter where we learn [[spoiler: Nana founded terrorist group Ares/Hades]].
* {{Bifauxnen}}: Shiro thinks that she is this because of her short hair and penchant for suits, but no one else does.
* BrainwashedAndCrazy: [[spoiler: Ares/Hades agents did this to a whole lot of Tripeace members]]
%% * CatGirl: [[MeaningfulName Neko.]]
* CoolMask: Tripeace agents wear blank masks with the Tripeace logo on it.
** SkullForAHead / SkeletonsInTheCoatCloset: Ares/Hades agents wear giant skulls on their heads, even in public.
* DespairEventHorizon:
** The point where [[spoiler: Shiro's mother thought she should've saved the bomb instead of Shiro]] is pretty low.
** Gen. Riboll claims [[spoiler: the deaths of his comrades]] is what fuels his over-the-top violence. It may have been true but it's plainly just an excuse now.
** The realization that [[spoiler: there will always be conflicts is what caused Nana to create Ares/Hades; it's also what Ares/Hades uses to brainwash Tripeace agents]].
* EvenEvilHasStandards: Ares/Hades agents, who are as dedicated to starting conflicts as Tripeace is to ending them, are disgusted by a man making a scene and picking fights in a diner full of families.
* FreudianExcuse: Hades' reason for spreading war is that [[spoiler: its members were once the people of a nation that achieved total peace. There was no need for weapons because there was no violence. But then the nations of the world took full advantage of this to mercilessly attack and ravage their home. So the people Hades have their old ideals a big middle finger for the stake of revenger.]]
* GoodScarsEvilScars: Nana has a prominent scar on his chest that is linked to his amnesia. Doctor Jack theorizes that if he's injured there, then he'll start to regain his memories. [[spoiler: It turns out he's right, and when Nana does, he becomes incredibly powerful and also has the chance to speak to his past self.]] In chapter 38 [[spoiler: a member of Hades nearly kills him by opening the wound in order to reawaken his memories. It works, and it's revealed that he was Hades' founder.]]
* PerfectPacifistPeople: A certain small country did away with internal strife and outlawed weapons and lived peacefully for years. [[spoiler: Then it was crushed by another country and out of the ashes came Ares/Hades.]]
* RetiredBadAss: [[spoiler: Gen. Riboll after the attack on his fortress.]]
* RuleOfThree: Tripeace, which follow the motto of "Peace, Love, and the third law." The third law is up to the members of Tripeace to choose for themselves individually. Shiro chooses [[spoiler: hope]] and Nana chooses [[spoiler: cross dressing.]] We also are initially introduced to three members of Tripeace.
* SlidingScaleOfIdealismVersusCynicism: Idealism side: Tripeace wants to end all wars forever; Cynical side (with a big scoop of {{revenge}}): Ares/Hades causes conflicts because [[HumansAreBastards there will *always* be conflicts.]]
* StupidSexyFlanders: Nana has a bad habit of unintentionally turning men on.
* TragicKeepsake:
** Nana's red ribbon, in memory of [[spoiler: the three kids who he befriends then sees being killed in the first chapter. Currently Nana has no memories of them but can't take the ribbon off]].
** Shiro's hairclip: [[spoiler: it's a memento of her mother and the bomb she was working on for peaceful purposes before it (and her mother) was twisted by Gen. Riboll]].
* UnusuallyUninterestingSight: Averted, the Ares/Hades agents know their giant skull masks are really noticeable in a normal diner.
* WellIntentionedExtremist: Tripeace is a heroic example.
* WholesomeCrossdresser:
** Nana as Nanako. It's revealed in chapter 38 that [[spoiler: he even did this back in his days as the lead member of Hades, and it was another method for him to kill people.]]
** [[spoiler: A young genius (who's also a defector from Ares/Hades) disguises himself as a girl, though for a different reason than Nana: he's not "manly" enough to be useful in battle so he figured he may as well be a girl.]]
* WoobieDestroyerOfWorlds: [[spoiler: When even the perfect pacifist nation that Nana and the rest of Ares/Hades came from was destroyed by war they decided to destroy everyone else in return.]]
--->[[spoiler: Nana]]: '''''[[{{Revenge}} IT IS TIME TO MAKE THE WORLD PAY FOR ALL THE SUFFERING THEY'VE PUT US THROUGH.]]'''''
* XMarksTheHero: Nana's scar is shaped like an X.