Anime with asexual (ace) and/or aromantic (aro) characters. Most are headcanons.
Manga version: https://animenew.net/stacks/29210
TV, 2018, 13 eps Me:- Author:8
Yuu Koito (demiromantic, demisexual/ace, and lesbian) (protagonist)
Touko Nanami (lithromantic and lesbian) (main)
Seiji Maki (aroace) (supporting)
TV, 2016, 120 eps Me:- Author:-
Kusuo Saiki (aroace) (protagonist)
TV, 2017, 12 eps Me:- Author:8
All gems (ace and pan) (main and supporting)
TV, 2017, 12 eps Me:- Author:-
Mito (aroace) (supporting)
TV, 2020, 12 eps Me:- Author:-
Shouko Tanimoto (aroace) (supporting)
TV, 2015, 24 eps Me:- Author:8
Makoto "Suna" Sunagawa (aroace) (main)
ONA, 2022, 12 eps Me:- Author:-
Anzu Hoshino (aro) (protagonist)
TV, 1999, ? eps Me:- Author:-
Monkey D. Luffy (aroace?) (protagonist)
TV, 2019, 24 eps Me:- Author:-
Senkuu (aroace) (protagonist)
TV, 2014, 12 eps Me:- Author:8
Umetarou Nozaki (aroace) (main)
TV, 2018, 13 eps Me:- Author:-
Mitsuyoshi Tada (aro?) (main)
TV, 2008, 13 eps Me:- Author:8
Takashi Natsume (aro?) (protagonist)
TV, 2005, 26 eps Me:- Author:8
Ginko (aro?) (protagonist)
TV, 2003, 13 eps Me:- Author:10
Kino (aro?) (protagonist)
TV, 2006, 37 eps Me:- Author:-
Light Yagami (aro?) (protagonist)
L Lawliet (aro?) (main)
TV, 2006, 25 eps Me:- Author:-
Lelouch Lamperouge (aro?) (protagonist)
Lloyd Asplund (aro?) (supporting)
TV, 2015, 24 eps Me:- Author:-
Souma Yukihira (ace?) (protagonist)
TV, 1998, 27 eps Me:- Author:-
Ryou Bakura (aroace?) (supporting)
TV, 2021, 20 eps Me:- Author:8
Fushi (ace?) (protagonist)
TV, 2017, 13 eps Me:- Author:6
Kobayashi (aro?) (protagonist)
TV, 1997, 276 eps Me:- Author:7
Satoshi/Ash Ketchum (aro?) (protagonist)
TV, 2017, 170 eps Me:- Author:-
Yuno (aro?) (main)
TV, 1986, 153 eps Me:- Author:-
Piccolo (aroace?) (supporting)
TV, 2012, 26 eps Me:- Author:-
Kars (aro?) (supporting)
TV, 2023, 24 eps Me:- Author:-
Maomao (aro?) (protagonist)
TV, 2014, 24 eps Me:- Author:-
Su-won (aro?) (supporting)
TV, 2004, 74 eps Me:- Author:8
Johan Liebert (aro?) (main)
Nina Fortner/Anna Liebert (aro?) (main)
TV, 2009, 11 eps Me:- Author:8
Akira "A-chan" Okudaira (ace/demisexual and lesbian) (main)
TV, 2003, 13 eps Me:- Author:2
Naozumi Sudo (aroace?) (supporting)
TV, 2013, 12 eps Me:- Author:7
Tomoki Kuroko (ace?) (supporting)
TV, 2013, 12 eps Me:- Author:-
Haruka "Haru" Nanase (aro?) (main)
TV, 2006, 14 eps Me:- Author:6
Yuki Nagato (aro?) (main)
TV, 2006, 26 eps Me:- Author:9
Haruhi Fujioka (demisexual and straight/NBLM) (protagonist)
TV, 2016, 12 eps Me:- Author:-
Tanaka (aro?) (protagonist)
TV, 2016, 12 eps Me:- Author:7
Sakamoto (aro?) (protagonist)
TV, 2010, 13 eps Me:- Author:7
Takatoshi Tsuda (ace?) (protagonist)
TV, 2015, 12 eps Me:- Author:7
Saitama (ace?) (protagonist)
TV, 2011, 13 eps Me:- Author:6
Shun Matsuoka (aroace?) (main)
TV, 2020, 12 eps Me:- Author:-
Catarina Claes (aroace?) (protagonist)
TV, 1999, 62 eps Me:- Author:-
Kurapika (aro?) (main)
TV, 2016, 22 eps Me:- Author:9
Rei Kiriyama (aro?) (protagonist)
TV, 2014, 12 eps Me:- Author:10
Sei "Seishuu" Handa (ace?) (protagonist)
Movie, 2006, 1 ep Me:- Author:7
Sawada (aroace?) (supporting)
TV, 2016, 13 eps Me:- Author:6
Mina "Pinky" Ashido (aro) (supporting)
TV, 2006, 12 eps Me:- Author:7
Balalaika (ace?) (supporting)
TV, 2012, 12 eps Me:- Author:-
Rikka Takanashi (ace/demisexual and straight?) (main)
ONA, 2018, 10 eps Me:- Author:7
Resasuke (aro?) (supporting)
TV, 2011, 60 eps Me:- Author:-
Tatsumi Oga (aroace?) (protagonist)
TV, 2011, 11 eps Me:- Author:8
Yoshino Takatsuki (aro?) (main)
TV, 2023, 28 eps Me:- Author:-
Frieren (aroace) (protagonist)