You should try this out if you haven’t read it yet!
http://www.mangago.zone/read-manga/koimonogatari/
Hmm I think these had a calm feeling to them generally ^ ^ some are also from the same author as blue sky complex sooo here~
http://www.mangago.zone/read-manga/slow_starter_ichikawa_kei/
http://www.mangago.zone/read-manga/cinema_next_door/
http://www.mangago.zone/read-manga/kimi_wa_natsu_no_naka/
http://www.mangago.zone/read-manga/number_call/
http://www.mangago.zone/read-manga/koi_saku_potager/
http://www.mangago.zone/read-manga/kocchi_muite_waratte/
http://www.mangago.zone/read-manga/blue_blue_blue/
http://www.mangago.zone/read-manga/itsuka_tomodachi_ja_nakunaru_to_shite_mo/
In addition to the excellent suggestions already made, maybe also these:
http://www.mangago.zone/read-manga/gunjou_no_subete/
http://www.mangago.zone/read-manga/doukyuusei_nakamura_asumiko/
http://www.mangago.zone/read-manga/bokura_no_shokutaku/
http://www.mangago.zone/read-manga/eigyou_nika/
http://www.mangago.zone/read-manga/mihanada_pectolite/
Looking for something similar to blue sky complex. A really chill seme and uke, slice of life, friends become lovers type story.