* BadLiar: She's not that good at making excuses for the fairies' mischief. Y explicitly calls her out on this during their school days.
* ChronicHeroSyndrome: Despite being overly pragmatic (and somewhat lazy), the Mediator will usually go out her way to help others. This was most prominently featured in episode 6, in which she [[spoiler:sabotages the electric generator in order to prevent P-ko and O-taro from leaving the solar system.]]
* DefrostingTheIceQueen: Starts off as an aloof and distant individual during the beginning of her first year in school. She loosens up after making friends.
* [[EveryoneCallsHimBarkeep Everyone Calls Her Mediator]]
* FireForgedFriends: Grows into this with Y, after the latter coughs up some interesting information on the individual members of the Wildrose Society...
* FirstPersonSnarker
** FirstPersonSmartass: She has her moments.
* [[spoiler: IJustWantToHaveFriends]]: [[spoiler: Episode 11 focuses almost entirely on this.]]
* [[NiceGuy Nice Girl]]: Beneath all that pessimism and apathy is a genuinely nice person.
* NoNameGiven: The ending credits list her as "[[{{Narrator}} Watashi]]".
* [[spoiler:PrehensileHair]]: A side effect of the [[spoiler:Fairy Co. hair grow Lotion]]
* SugarAndIcePersonality: Aloof and standoffish (more so when she was younger) but a sweetheart when you get right down to it.
* SweetTooth: Possibly, seeing as how she bakes sweets as a hobby.
* [[TheSmartGuy The Smart Girl]]
* TheStoic: Very much so.
* TheReasonYouSuckSpeech: [[spoiler: Delivers a particular nasty one to Y when they were in school.]]
* {{Tsundere}}: During her school days.
* TheCynic
* [[spoiler: IJustWantToHaveFriends]]: During her younger years.
* LargeHam : When she's talking about her [[YaoiFangirl passion]].
* {{Shipping}}: Invoked and spoofed, she ships ''chess'' ''pieces''!
* TsurimeEyes
* YaoiFangirl: Becomes her source of income.

* CuteMute
* NoNameGiven
* WildChild: Just hidden by the fact he doesn't speak

* CatGirl
* EverybodyKnewAlready: It becomes fairly obvious that Pion is not human as the story goes on, but she only reveals the fact towards the end of her story.
* MagicSkirt: Just how is she able to fight in a skirt like ''that''...?
* ScarfOfAsskicking: And boy, does she ever.
* UnfortunateName: Which leads to the Mediator to give her the nickname of P-ko.
* VerbalTic: Ends sentences with "de arimasu", further lending to her weird personality.

!Oyage/Otaro [[spoiler: Voyager]][[quoteright:225:http://static.tvtropes.org/pmwiki/pub/images/860593293364_9051.jpg]]
A strange character, that appears in episode 6, and the target of the Pion's Mission, and is implied they are somehow related. [[spoiler: latter in the show is explained as he is the AnthropomorphicPersonification of the Space probe Voyager, that has gained self awareness and desired return to earth, forcing Pion to seek for him]]

* AnthropomorphicPersonification: [[spoiler: Of the deep Space Probe Voyager]]
* CallingYourAttacks
* DoAndroidsDream: [[spoiler:Its revealed that the reason he return to earth is because he felt alone in the immensity of the space.]]
* GratuitousEnglish
* EveryoneCallsHimBarkeep: A odd example. As with Pion's name, its formed for some letters [[spoiler: they remember of their real names]] being adapted into Japanese names ("O" and the suffix "-taro", that denotes a male name), but is revealed that his name is [[spoiler: V''oyage''r, just as the spacial Voyager Program]], so overlaps with HisNameReallyIsBarkeep.
* MoeAnthropomorphism
* MegaNeko: Killer Death Cat, his ultimate form, ''somehow.''
* MotorMouth: Talking about the Behemoth Bulldozer he built.
* ScarfOfAsskicking: Trademark alongside with Pion/Piko. Its that so that he even uses it when in the Big Brother Suit
* ShoutOut: He gets a [[Franchise/BioShock Big Brother Suit]] out of nowhere in episode 6.
* SpearCounterpart: To Pion.
* TechnoBabble: all of the specifications of the Behemoth are this, including a Old Wise Brain as a CPU and a Super Stellar Motor.
* TsurimeEyes
* [[YouGottaHaveBlueHair You Gotta Have Cyan Hair]]