http://www.mangago.me/read-manga/welcome_to_the_impregnable_demon_king_castle_the_black_mage_who_got_kicked_out_of_the_hero_party_due_to_his_unnecessary_debuffs_gets_welcomed_by_the_top_brass_of_the_demon_king_s_army/
already in fantasy world, He does have a fan who is one of the female demon generals and she's always fangirling over him but that's just for comedy(no actually romance)
http://www.mangago.me/read-manga/levelling_up_by_only_eating/
Not Isekai, most of webcomic is spent within the MMROPG game, but the character and setting you were looking for, very light hearted, so funny and the mc is nothing but an op cute foodie (no love interest either)
http://www.mangago.me/read-manga/trash_of_the_count_s_family/uu/nhs_chapter-774323/
ace as heck, woke up one day and was isekaied into the body of the main antagonist in a book he was reading and just trying to made the most out of the sitch he's in, v interesting plot, slow paced but worth it
http://www.mangago.me/read-manga/suterareta_tensei_kenja_mamono_no_mori_de_saikyou_no_dai_ma_teikoku_o_tsukuriageru/
already in fantasy world, reincarnated and trying to redevelop the magical strength he once had while being a little kid, no love interest and same end goal as Time I Reincarnated into a Slime, to built a place for monsters, fairly new but every chapter is very good
http://www.mangago.me/read-manga/yakuza_reincarnation/
Yakuza gets isekaied during turf war into the body of a princess, definitely different then any man isekaied into op girl I've seen and the art is amazing tho fight scenes can get a little busy but with awesome detail. The plot does get lost at times, but you still know what's going on and its also pretty funny too, martial arts and gore cuz sometimes a yakuza turnt princess needs to beat villains to a pulp
can someone gimme recs on isekai with a most likely ace mc or like no girls falling for mc and annoying shit like that please? just saying, i've already http://www.mangago.me/read-manga/tondemo_skill_de_isekai_hourou_meshi/ so uh, yeah.