https://www.mangago.zone/read-manga/dark_heaven/
https://www.mangago.zone/read-manga/murderer_llewellyn_s_enchanting_dinner_invitation/
https://www.mangago.zone/read-manga/cold_blooded_beast/
https://www.mangago.zone/read-manga/tale_of_the_yellow_dragon/
https://www.mangago.zone/read-manga/love_sick_dog/
https://www.mangago.zone/read-manga/the_man_who_can_t_taste/
https://www.mangago.zone/read-manga/ways_of_parting/
https://www.mangago.zone/read-manga/doppleganger/
'This ending'-- i don't really remember how it ends but it has a sad vibe overall, it's about a fading love so yea
'Timeless melody'-- it's like a bittersweet story, I can't exactly give much details without spoilers, but the story is good, tho some people do say it was made with reference to some irl idols so idk how to feel about that
This is like exactly what you’re looking for:
https://www.mangago.zone/read-manga/cosmic_boy/
Give a bl that's so tragic at the start and nearing the end they only finally make things right but during the tragic their not a bad person just misunderstood feelings between the two of worry like traces of the sun, The S-Class Guide as Sweet as Honey, don't mess with the pup and more like plz ٩(๑❛ᴗ❛๑)۶