If you want something complex try Moritat it's complex as hell x) but it's shonen-ai :/
ff.
http://www.mangago.zone/read-manga/complex_manda_ringo/
http://www.mangago.zone/read-manga/dark_heaven/
http://www.mangago.zone/read-manga/escape_into_oblivion/
http://www.mangago.zone/read-manga/tourou_no_ori/
http://www.mangago.zone/read-manga/warehouse/
http://www.mangago.zone/read-manga/sakura_gari/
http://www.mangago.zone/read-manga/zankoku_na_kami_ga_shihai_suru/
definitely complex but not unrequited love nor childhood first love
Can someone recommend some complex yaoi? Would prefer if it was unrequited love or where they fall in love as children or something like that thanks I advance