Stuff without romance?

The best story I know of that has NO ROMANCE, ZERO FANSERVICE AND ABSOLUTELY NO SEXUALISATION, ESPECIALLY OF IT'S FEMALE CAST, is of course the BEST new-gen DARK FANTASY, ACTION SHOUNEN MANGA of the 2020s, the peak of human literature, Kagurabachi! If you're looking for a story with a more slow-burning pacing and world-building, but masterfully-written plot, realistically written and interesting characters with great designs, GORGEOUS ART that evolves with each new chapter, MOVIE-LIKE fighting choreography, BEAUTIFUL panelling and composition! GO READ IT NOW!!

https://www.mangago.me/read-manga/kagurabachi/ (PEAK FICTION)

Also these other shounen/seinen (mostly action) mangas don't feature romance:
https://www.mangago.me/read-manga/gokurakugai/
https://www.mangago.me/read-manga/windbreaker/
https://www.mangago.me/read-manga/tokyo_aliens/
https://www.mangago.me/read-manga/gachiakuta/
https://www.mangago.me/read-manga/galaxias/
https://www.mangago.me/read-manga/centuria/
https://www.mangago.me/read-manga/psycho_eyes/
https://www.mangago.me/read-manga/g_g_g/
https://www.mangago.me/read-manga/chainsaw_man/
https://www.mangago.me/read-manga/ultimate_exorcist_kiyoshi/
https://www.mangago.me/read-manga/madan_no_ichi/
https://www.mangago.me/read-manga/tongari_boushi_no_atelier/
https://www.mangago.me/read-manga/magical_girl_and_narco_wars/
https://www.mangago.me/read-manga/the_marshal_king/
https://www.mangago.me/read-manga/kai_hen_wizards/
https://www.mangago.me/read-manga/ruby_on_the_cake_hitogui_majo_no_bansankai/

Knight of embers
Hand jumper
Study group
The build up
The boxer
Sweet home
Shotgun boy
Pigpen
Eleceed
Look back
Goodbye eri
Hwaja
Pyramid game
Survive romance (there's no actual romance)
Night of Shadows
Bastard

Stardust family
Going home to mom

https://www.mangago.me/read-manga/the_dependable_delinquents_daily_lives/

https://www.mangago.me/read-manga/penguin_kissa_wa_kyo_mo_seiten/

https://www.mangago.me/read-manga/hello_veterinarian/

https://www.mangago.me/read-manga/meiou_no_zakuro/

https://www.mangago.me/read-manga/the_evil_ring/

https://www.mangago.me/read-manga/mofumofu_to_mukumuku_to_isekai_hyouryuu_seikatsu/

https://www.mangago.me/read-manga/the_delusional_hunter_in_another/

https://www.mangago.me/read-manga/good_morning_leon/

https://www.mangago.me/read-manga/hosomura_san_and_the_cat_s_snack/

https://www.mangago.me/read-manga/sekai_wo_teki_ni_mawashitemo_neko_wo_aishiteru/

https://www.mangago.me/read-manga/aisaretagari_no_shironeko_miko_san/

https://www.mangago.me/read-manga/taro_miyao_becomes_a_cat_parent_official/

https://www.mangago.me/read-manga/neko_ga_gotoku/

https://www.mangago.me/read-manga/ojisama_to_neko/

https://www.mangago.me/read-manga/cat_on_the_hero_s_lap/

https://www.mangago.me/read-manga/one_room_dog/

https://www.mangago.me/read-manga/meow_meow/

https://www.mangago.me/read-manga/old_man_and_nyankichi/

https://www.mangago.me/read-manga/obssesed_butler/

https://www.mangago.me/read-manga/neko_s_massage_salon/

https://www.mangago.me/read-manga/isekai_mofumofu_cafe/

https://www.mangago.me/read-manga/the_life_of_a_grandpa_cat/

https://www.mangago.me/read-manga/she_doesn_t_know_why_she_lives/

https://www.mangago.me/read-manga/yoru_san_no_itoshi_no_bansan/

https://www.mangago.me/read-manga/black_cat_and_soldier/

https://www.mangago.me/read-manga/mine_kun_is_asexual_official_translation/

https://www.mangago.me/read-manga/a_story_about_a_cat_reincarnated_in_a_different_world_where_there_are_no_cats/

https://www.mangago.me/read-manga/hiroware_koneko_to_moto_yakuza/

https://www.mangago.me/read-manga/sennen_meikyuu_no_nana_ouji/

https://www.mangago.me/read-manga/please_call_me_red_panda/

https://www.mangago.me/read-manga/shiba_inu_rooms/