I don't really know if these are really similar with the series or if you'll like it but here it goes:
A guide to proper dating
http://www.mangago.zone/read-manga/a_guide_to_proper_dating/
Our relationship is
http://www.mangago.zone/read-manga/our_relationship_is/?HHW6
I hate love (up to ch 46 but twas last updated oct 2018)
http://www.mangago.zone/read-manga/i_hate_love/
The only love i know
http://www.mangago.zone/read-manga/the_only_love_i_know/
Timid palette
http://www.mangago.zone/read-manga/timid_palette/
Best wolf in my life
http://www.mangago.zone/read-manga/the_best_wolf_in_my_life/
Perfect relationship
http://www.mangago.zone/read-manga/perfect_honeymoon/
Cat amd dog
http://www.mangago.zone/read-manga/cat_and_dog_park_hee_jung/
Gradually cose to the heart
http://www.mangago.zone/read-manga/gradually_close_to_the_heart/
Here are some more~
http://www.mangago.zone/read-manga/please_stamp_me/
http://www.mangago.zone/read-manga/gatabutata/
http://www.mangago.zone/read-manga/touch_touch_you/
http://www.mangago.zone/read-manga/all_i_want_is_who/
http://www.mangago.zone/read-manga/one_of_a_kind_romance/
http://www.mangago.zone/read-manga/today_living_with_you/
http://www.mangago.zone/read-manga/bunny_and_her_boys/
http://www.mangago.zone/read-manga/a_falling_cohabitation/
http://www.mangago.zone/read-manga/so_i_married_an_anti_fan/
http://www.mangago.zone/read-manga/beware_of_your_boyfriend/
http://www.mangago.zone/read-manga/miss_time/
http://www.mangago.zone/read-manga/in_the_mood_for_love/
http://www.mangago.zone/read-manga/my_oppa_is_an_idol/?zyee
Although this one only has 2 updates
http://www.mangago.zone/read-manga/play_playlist/
Forgive me if these stories did not pass your taste. Tho for me they really give off the same aura as shadow window couple. But I still hope you enjoy! (◕‿◕✿)
Anyone have any recommendations like this??? I really like the characters personalities :))