Isekai:
https://www.mangago.me/read-manga/miss_not_so_sidekick/
https://www.mangago.me/read-manga/anyone_can_become_a_villainess/
https://www.mangago.me/read-manga/death_is_the_only_ending_for_the_villainess/
https://www.mangago.me/read-manga/as_you_wish_prince/
https://www.mangago.me/read-manga/i_became_the_tyrant_s_secretary/
https://www.mangago.me/read-manga/why_she_lives_as_a_villainess/
https://www.mangago.me/read-manga/i_became_the_hero_s_mom/
https://www.mangago.me/read-manga/i_m_the_male_lead_s_girl_friend/
https://www.mangago.me/read-manga/beware_of_the_red_thread/
https://www.mangago.me/read-manga/beware_of_the_villainess/
https://www.mangago.me/read-manga/i_met_the_male_lead_in_prison/
https://www.mangago.me/read-manga/marilyn_likes_lariensa_too_much/
https://www.mangago.me/read-manga/i_m_not_a_villainess_just_because_i_can_control_darkness_doesn_t_mean_i_m_a_bad_person/
https://www.mangago.me/read-manga/maou_no_migiude_ni_nattanode_gensaku_kaiaku_shimasu/
https://www.mangago.me/read-manga/i_ll_become_the_tyrant_s_tutor/
https://www.mangago.me/read-manga/the_villain_discovered_my_identity/
https://www.mangago.me/read-manga/saving_the_villain_who_was_abandoned_by_the_female_lead/
https://www.mangago.me/read-manga/i_m_a_martial_art_villainess_but_i_m_the_strongest/
https://www.mangago.me/read-manga/i_ve_become_the_villainous_emperor_of_a_novel/
https://www.mangago.me/read-manga/i_became_the_ugly_lady/
https://www.mangago.me/read-manga/i_ll_do_that_marriage/
https://www.mangago.me/read-manga/seduce_the_villain_s_father/
https://www.mangago.me/read-manga/the_younger_male_lead_fell_for_me_before_the_destruction/
https://www.mangago.me/read-manga/villainous_princess/
https://www.mangago.me/read-manga/i_m_the_ex_girlfriend_of_a_soldier/
https://www.mangago.me/read-manga/my_sister_picked_up_the_male_lead/
https://www.mangago.me/read-manga/the_lady_s_butler/
https://www.mangago.me/read-manga/higeki_no_genkyou_tonaru_saikyou_gedou_rasubosu_joou_wa_tami_no_tame_ni_tsukushimasu/
https://www.mangago.me/read-manga/the_lady_i_served_became_a_young_master/
https://www.mangago.me/read-manga/the_evil_cinderella_needs_a_villain/
https://www.mangago.me/read-manga/jishou_akuyaku_reijou_na_konyakusha_no_kansatsu_kiroku/
https://www.mangago.me/read-manga/the_reincarnated_villainess_dark_history/
https://www.mangago.me/read-manga/wish_to_say_farewell/
https://www.mangago.me/read-manga/limited_time_princess/
https://www.mangago.me/read-manga/i_will_change_the_genre/
Isekai but the leads don't know the story/it doesn't really show that it's a story/game just that they have transmigrated so they don't know what's gonna happen:
https://www.mangago.me/read-manga/college_student_empress/
https://www.mangago.me/read-manga/the_maid_and_the_vampire/
https://www.mangago.me/read-manga/a_night_with_the_emperor/
https://www.mangago.me/read-manga/happy_ending_for_the_time_limited_villainess/
https://www.mangago.me/read-manga/charming_and_the_beast/
https://www.mangago.me/read-manga/the_lady_s_law_of_survival/
https://www.mangago.me/read-manga/i_want_to_become_the_hero_s_bride/
https://www.mangago.me/read-manga/his_highness_don_t_leave_i_will_lose_weight_for_you/
https://www.mangago.me/read-manga/itan_empire_s_jacheongbi/
https://www.mangago.me/read-manga/i_raised_cinderella_preciously/
https://www.mangago.me/read-manga/the_moon_witch_and_the_sun_king_my_salvation/
https://www.mangago.me/read-manga/princess_wars/
https://www.mangago.me/read-manga/empress_of_another_world/
https://www.mangago.me/read-manga/royal_shop_of_young_lady/
https://www.mangago.me/read-manga/iris_lady_with_a_smartphone/
https://www.mangago.me/read-manga/sweetheart_v5_the_boss_is_too_kind/ (here the fl gets transmigrated into the future)
Not isekai, the fls go back in time in their own lives:
https://www.mangago.me/read-manga/the_villainess_reverses_the_hourglass/
https://www.mangago.me/read-manga/the_abandoned_empress/
https://www.mangago.me/read-manga/lady_baby/
https://www.mangago.me/read-manga/angelic_lady/
https://www.mangago.me/read-manga/actually_i_was_the_real_one/
https://www.mangago.me/read-manga/the_villainess_lives_twice/
https://www.mangago.me/read-manga/it_s_no_use_hanging_on/
https://www.mangago.me/read-manga/what_it_means_to_be_you/
https://www.mangago.me/read-manga/untouchable_lady/
https://www.mangago.me/read-manga/duchess_of_the_glass_house/
https://www.mangago.me/read-manga/a_way_to_protect_you_sweetheart/
https://www.mangago.me/read-manga/i_ll_be_the_matriarch_in_this_life/
https://www.mangago.me/read-manga/return_of_the_female_knight/
https://www.mangago.me/read-manga/a_poisonous_lily/
https://www.mangago.me/read-manga/a_silent_garden/
https://www.mangago.me/read-manga/daisy_lisabel/
https://www.mangago.me/read-manga/lucia/
https://www.mangago.me/read-manga/priscilla_s_marriage_request/
https://www.mangago.me/read-manga/aidin/
https://www.mangago.me/read-manga/the_tyrant_husband_has_changed/
https://www.mangago.me/read-manga/a_stepmother_s_m_rchen/
https://www.mangago.me/read-manga/the_duchess_with_an_empty_soul/
https://www.mangago.me/read-manga/the_goal_is_to_become_a_gold_spoon_so_i_need_to_be_completely_invulnerable/
https://www.mangago.me/read-manga/tearmoon_empire_story/
https://www.mangago.me/read-manga/a_villain_is_a_good_match_for_a_tyrant/
https://www.mangago.me/read-manga/your_majesty_please_don_t_kill_me_again/
https://www.mangago.me/read-manga/the_emperor_reverses_time/ (here the male lead reverses time to make his wife happy in this life cause in the past he neglected her)
https://www.mangago.me/read-manga/the_villain_demands_i_love_him/ (here too the ml is the one who remembers the past)
Not isekai, the fls stand up for themselves in the same timeline:
https://www.mangago.me/read-manga/the_great_wish/
https://www.mangago.me/read-manga/beatrice/
https://www.mangago.me/read-manga/a_hunter_s_courtship_method/
https://www.mangago.me/read-manga/bring_the_love/
https://www.mangago.me/read-manga/i_don_t_love_you_anymore/
https://www.mangago.me/read-manga/under_the_oak_tree/
https://www.mangago.me/read-manga/don_t_call_me_sister/
https://www.mangago.me/read-manga/an_inescapable_love/
https://www.mangago.me/read-manga/the_sacrificial_princess/
https://www.mangago.me/read-manga/crows_like_shiny_things/
https://www.mangago.me/read-manga/the_fake_princess_op_bunny/
https://www.mangago.me/read-manga/i_gave_birth_to_the_tyrant_s_child/
https://www.mangago.me/read-manga/a_capable_maid/
https://www.mangago.me/read-manga/irregular_empress/
https://www.mangago.me/read-manga/the_duchess_lewd_invitation/
https://www.mangago.me/read-manga/revenge_wedding/
https://www.mangago.me/read-manga/remarried_empress/
https://www.mangago.me/read-manga/my_new_wife_is_forcing_herself_to_smile/ (one-shots of a really cute couple who like each other but cannot express it)
https://www.mangago.me/read-manga/endo_and_kobayashi_s_live_commentary_on_the_villainess/ (not isekai but some people in the video game can hear the players in real life and have minds of their own)
romance isekai anyone?