Examples of FirstNameBasis in FanFiction.
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* In ''Fanfic/KyonBigDamnHero'', members of the SOS Brigade change the way they address each other as a symbol of their TrueCompanions relationship is strengthening: Tsuruya is called ''Tsu-chan'' by Haruhi and Mikuru(big), and Yuki and Mikuru being called by their first names not only by Haruhi.
* Used in the ''Series/TheXFiles'' / ''EarthFinalConflict'' crossover "Apologia." The young Agent Sandoval asks if he can address Scully as "Dana," because he refuses to give the impression that he's trying to take Mulder's place.
* A classic example of this trope appears in ''Fanfic/WithStringsAttached'' [[spoiler: when, as a sign of his complete HeelFaceTurn, the Hunter asks Paul to start calling him by his first name, Jim. He had already agreed to use the first names of the four that morning, rather than the insulting nicknames he'd come up with for them at the beginning]]. (Originally, when George said that they have names and would he care to hear them, he said “Not especially.”)
* In the KatawaShoujo fic "From Shizune's Perspective," Shizune temporarily switches to calling Emi by her first name rather than "Miss Ibarazaki" to make a point, then despite switching back to calling her by her last name, gradually switches over to her first name. She also points out that Hisao might be "interested" in Emi if he calls her by her first name, causing Misha to react in displeasure [[spoiler:because she is in love with Hisao]]. Shizune also calls Misha by her first name, Shiina, in this fic, instead of her nickname.
* In ''Fanfic/AceCombatTheEquestrianWar'', [[{{TheEngineer}} Lightning Bolt]], [[{{BadassBookworm}} Twilight Sparkle]] and [[{{OriginalCharacter}} Tornado Swirl]] are usually called Lightning, Twilight and Tornado. [[{{PluckyGirl}} Cloud Kicker]] also applies to this, though rarely.
* Jessica Poole gets onto this with ApolloJustice during the second day of investigation in ''TurnaboutSubstitution'', but retracts it the next day, much to Apollo's surprise.
* In ''Fanfic/ACompleteTurnabout'', one of the first clues that Phoenix gets regarding his new place in an alternate universe is that [[OOCIsSeriousBusiness Edgeworth calls him "Phoenix"]] instead of [[LastNameBasis "Wright,"]] like canon!Edgeworth always does.
* A major part of Vinyl Scratch's CharacterDevelopment in [[http://www.fimfiction.net/story/79494/vinyl-and-octavia-machete-their-way-through-the-jungle Vinyl and Octavia Machete Their Way Through The Jungle]] is the fact that she stops calling Octavia names like Tavi and Octy and instead calls her by her full name.
* ''Fanfic/CalvinAndHobbesIIIDoubleTrouble'' has two characters named Rupert Chill - one human, one alien. The alien Rupert goes by his first name to avert confusion.
* Nav from ''FanFic/DiariesOfAMadman'' tends to be on first name terms with almost everyone he meets, royalty and commoners alike. Strangely enough, it's usually those accompanying him that protest over the lack of formality, rather than the recipients.
* Yuzu and Byakuya ran the whole gamut of names and titles in the ''{{Manga/Bleach}}'' fanfics ''[[https://www.fanfiction.net/s/6902577/1/Phases-of-the-Moon Phases of the Moon]]'' and ''[[https://www.fanfiction.net/s/8222340/1/Chasing-the-Moon Chasing the Moon]]''. While Yuzu was in the Academy and Byakuya was helping her train, Yuzu called him "Kuchiki-dono" (Lord Kuchiki) and Byakuya called her [[FullNameBasis "Kurosaki Yuzu"]] [[HeyYou (if he called her anything at all)]]. While Yuzu was still an Academy student but chose to actively involve herself in a battle for the first time, she called him "Kuchiki-taicho" (Captain Kuchiki), signifying that she now sees herself as a shinigami and a (future) member of the Gotei 13. Ten years later, by the time of the sequel, Byakuya now calls her [[LastNameBasis "Kurosaki"]], seeing as she's now his vice-captain, and Yuzu starts referring to him almost exclusively as "Taicho" (just plain Captain). As the WillTheyOrWontThey intensifies, they start ''thinking'' each other's first names without actually saying them out loud. They ''finally'' make it to FirstNameBasis [[SayMyName at the end of ''Chasing The Moon's'' penultimate arc.]] [[spoiler: Too bad it happens in the last moment before Yuzu runs off on a SuicideMission that appears to be UnwinnableByDesign.]]
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