http://www.mangago.zone/read-manga/path_to_you/
http://www.mangago.zone/read-manga/suspicious_guest_and_the_part_timer/
These two are really cute and short (๑•ㅂ•)و✧
You asked for masterpieces so I picked them from my list of faves, hope you'll find something you enjoy!
http://www.mangago.zone/read-manga/hyperventilation/
http://www.mangago.zone/read-manga/dear_signal/
http://www.mangago.zone/read-manga/koi_wo_suru_tsumori_wa_nakatta/
http://www.mangago.zone/read-manga/neon_sign_amber/
http://www.mangago.zone/read-manga/jackass_sawatte_ii_tte_dare_ga_itta_yo/
http://www.mangago.zone/read-manga/karasugaoka_don_t_be_shy/
http://www.mangago.zone/read-manga/konosaki_wa_futarikiride/ (though the unrequited part doesn't last for long)
http://www.mangago.zone/read-manga/isso_koe_ga_nakattara/
http://www.mangago.zone/read-manga/kakkou_no_yume/
http://www.mangago.zone/read-manga/boku_wa_kimi_no_iinari/
http://www.mangago.zone/read-manga/tsukiyo_no_kurage_wa_koi_ni_naku/
http://www.mangago.zone/read-manga/shangri_la_no_tori/
Please give me some shorter masterpiece where uke has unrequited, puppy love for seme and they end up together eventually and it’s not a tragedy or I’ll read Beautiful days again. the number of times I’ve reread this is not healthy haha:DD