Can you recommend any yaoi manga where the main characters are childhood friends, get separated, and fall in love after reuniting?
Surprisingly, there aren't many BLs with that premise (that I know of). This is somewhat similar:
https://www.mangago.zone/read-manga/bokura_no_tsuzuki/
Also this if you don't mind manhua:
https://www.mangago.zone/read-manga/leo/
But in both stories the protagonists reunite during high school. I wish there was something where they reunite as adults. Maybe someone else knows one.
Do you know of a manga with a neighbour or something who knows the seme as a child and later gets together with him?
Seme also had a crush on the uke as a child, I think. But it wasn't grooming! So the uke just thought Seme was cute as a kid!
This one? https://www.mangago.zone/read-manga/home_tsuyuki_yuruko/ (idk, if this is what you are asking for but, I find the age gap huge, but... shakes my head in * this witch of mine * )
Do you know any yaoi or shonen ai fanfic here with Satoru und Suguru? (=・ω・=)
https://www.mangago.zone/read-manga/patonaga_zenzen_okinakute_komaru_jujutsu_kaisen_dj/
https://www.mangago.zone/read-manga/jujutsu_kaisen_dj_saiai/
https://www.mangago.zone/read-manga/jujutsu_kaisen_dj_terminal_lucidity_eng/
https://www.mangago.zone/read-manga/let_me_in_jujutsu_kaisen_dj/
https://www.mangago.zone/read-manga/kimi_ni_sasagu_jujutsu_kaisen_dj/
https://www.mangago.zone/read-manga/jujutsu_kaisen_dj_kura_no_ryuukeichi/
Yes, I know a website for more but I don't know if I can share it or not
What is your most beloved completed story?
All genres allowed!
BLs
https://www.mangago.zone/read-manga/dekoboko_bittersweet_days/
https://www.mangago.zone/read-manga/dekoboko_sugar_days/
https://www.mangago.zone/read-manga/twilight_amrita/
https://www.mangago.zone/read-manga/december_rain/
https://www.mangago.zone/read-manga/ii_ko_ii_ko_shiteageru/
https://www.mangago.zone/read-manga/wild_rock/
https://www.mangago.zone/read-manga/heart_stain/
If you ask so I don't have much just these (▰˘◡˘▰)
https://www.mangago.zone/read-manga/randen_to_saga/
https://www.mangago.zone/read-manga/neko_x_neko/
https://www.mangago.zone/read-manga/imouto_wa_neko/
https://www.mangago.zone/read-manga/the_farthest_friend/
https://www.mangago.zone/read-manga/cheerful_amnesia/
https://www.mangago.zone/read-manga/the_boy_with_no_interest_in_love_and_his_genderswapped_best_friend/
https://www.mangago.zone/read-manga/his_fingers_are_always_wet/
https://www.mangago.zone/read-manga/asagao_to_kase_san/
https://www.mangago.zone/read-manga/scorching_romance/
https://www.mangago.zone/read-manga/secret_closet/
https://www.mangago.zone/read-manga/chemical_romance/
Etc. Etc.

Do you have a yaoi manga with forbidden love? :)