A list of the majority of my aro/ace-spec headcanons:
Hatake Kakashi from Naruto - pretty self-explanatory.
Chisato Mera from The disastrous life of Saiki K - "cake is better than romance" is the vibe I got from her in that one episode where Saiki turns into a girl. (season 2 episode 1, I think)
Serinuma Kae from Kiss him not me - she's only ever had crushes on fictional characters and even at the end of he anime she can't choose a partner. I am aware that she ends up marrying Mutsumi-senpai in the manga, but even that I feel like is a qpr marriage.
Auriana from Lolirock - she's always flirting with boys, but it's not far-fetched to headcanon that she only likes how they look. After all, she never actually enters a long-term relationship. (she's also adhd)
Lakan from The apothecary diaries - I believe he is 100% aromantic, but demisexual. He only started feeling attraction towards his not-so-soon-to-be-wife after they played many games of chess (?) (i might remember wrong) , which was represented by him becoming capable of seeing her face. (this man is so autistic)
Aburame Shino from Naruto - yet another delightfully autistic character! Not much to say about him though.
Kazuki Tsukasa from Romantic killer - I wasn't sure if I wanted to headcanon him as aroace or only as aro. Anyway, he's demi.
Qiao Ling from Link Click - she's cupioromantic in my headcanon. No reasoning.
Teruhashi Kokomi from Saiki K - has only ever had one genuine crush.
Lu Guang from Link Click - demiest man alive. Also autistic.
Cheng Xiaoshi from Link Click - he's 1000% aroace, but filled with all the platonic love a person could possibly feel. Qpr Shiguang. (also adhd)
Susie from Deltarune - either greyro+greyace or reciproro+reciproace.
Pinkie Pie - gives me the same vibes as Cheng Xiaoshi. QPR with Cheese Sandwich. (+BPD and autism HSJQJSJ)
Talia from lolirock - potentially romance repulsed, but still supportive of her friend's relationships.
Nozaki from Monthly girls Nozaki-kun - he's the only non-bi character in his show and I find that hilarious.
Anya Forger - yes, I know, she's a child, but, just saying, all her schoolmates are very interested in romantic stuff, meanwhile she's the only one like "I only like shows that have fighting in them" ( me too girl, me too).
Lin Yutong and Tan Weiyun from Don't say you love me - I'm pretty sure both of them are canonically demi. Otherwise pan? I feel like gender doesn't matter to Weiyun either.
Hairou Kineshi from Saiki K.
Rouxls Kaard from Deltarune - this might come as a surprise. However, I already talked about this headcanon on my blog before. He only joined the polycule for more power. He's stupid.
Maki from Bloom into you.
Henry Henderson from Spy x family - he definitely felt alterous attraction towards Martha and wanted a QPR with her.
Inuzuka Kiba from Naruto - I do also like the headcanon that he has a crush on Hinata, but he's also super supportive of Naruhina, so...
Saiki Kuusuke from Saiki K - are you ven surprised? Offu.
Berdly from Deltarune - again, are you surprised?
Hoshino Anzu from Romantic killer. Fictosexual. Hoshino was her family name, right?
Koito Yuu from Bloom into you - demi.
Uchiha Sasuke - is in love with Naruto.
Tenna from Deltarune - biromantic. Spamtenna and Queentenna. Also shoutout to his bpd.
Seam from Deltarune - idk what their romantic orientation is, but I feel like they only like one gender.
Mutsumi from Kiss him not me - in a qpr marriage with Serinuma. Aromantic person x Asexual person relationship ! Also maybe he's autistic?
Mao Mao from The apothecary diaries - 100% ace, but will probably fall in love with Jinshi. She's just as autistic as both of her fathers (biological and adoptive).
The entire cast of Ruri rocks. All audhders. Need I say more?
Cowboy Mike/Jongler from Deltarune. QPR polymikes.
Kuboyasu Aren from Saiki K.
And in the last one I'm maknly referring to the black haired guy, whose name I think was Qin Weihang. From Lemon lightning. Man, I miss that comic, it was very cute.
A few Spy x Family edits! We have QPR Loid x Yor, aromantic Henry, QPR Henry x Martha, asexual director of State Security Service, probably with the name Wylker, but I don't remember too well, and AAA battery Henry.