Best friends:
http://www.mangago.me/read-manga/itsuka_tomodachi_ja_nakunaru_to_shite_mo/
http://www.mangago.me/read-manga/king_prince/ (ch 3 and 4)
http://www.mangago.me/read-manga/walking_with_you_junko/
http://www.mangago.me/read-manga/negative_kun_to_positive_kun/
http://www.mangago.me/read-manga/mazu_wa_hitokuchi/
Maybe something from these(mostly childhood friends and one of the sides didn't notice):
http://www.mangago.me/read-manga/u_don_t_know_me/
http://www.mangago.me/read-manga/kiss_ja_tomaranai/
http://www.mangago.me/read-manga/kimi_wo_mukaeni/
http://www.mangago.me/read-manga/tonari_ni_iru_no_ni_tooi/
http://www.mangago.me/read-manga/dekichatta_danshi/
http://www.mangago.me/read-manga/omairi_desu_yo/
http://www.mangago.me/read-manga/i_cant_even_breeth_without_you/
http://www.mangago.me/read-manga/konya_mo_jirettai/
http://www.mangago.me/read-manga/kanga_na_spoon/
http://www.mangago.me/read-manga/me_o_tojite_3_byou/
http://www.mangago.me/read-manga/boku_to_neko_to_hatsukoi_kousa/
I'm obsessed wif best friends shounen ai manga like 19 days mahwa or it could be more lovey dovey. More like they're best friends but didn't really notice but along the way they thought
"Ya..he's important to me.." and such. Try to avoid childhood best friends if possible or not its okay *thumbs up*(it's okay if it's yaoi too I guess but I like it if it's light n make u laugh, you know?)
Pls help and thanks alot!