This one historical example already has an anime, multiple mangas, movie adaptations, tv shows, games, etc...
When you look at it from an outsider perspective, seeing a "real life black samurai" feels like a cool idea especially for people who may see themselves being "represented", and even for japanese it's still an interesting concept. But at the same time it shows how people are willing to ignore actual history in favor of what they think it's cool or what aligns to their beliefs. In the case of Yasuke no one seems to read beyond "Nobunaga had a black person as a retainer" while
even a simple wikipedia search shows that he was, in the end, nothing more than a pet, a curiosity a local nobleman found weird enough to buy. The truth is he wasn't important enough for history to record anything about his life outside of the 15 months he served Nobunaga (no one knows his birth place, no one knows his real name, no one knows where his grave is). For all intent and purposes he was nothing more than a slave who traveled to Japan together with his master (an italian jesuit missionary), was noticed by Nobunaga simply because of his black skin (and he didn't believe him to be actually black at first, he had his servants remove his clothes and wash him to see if the black skin was inked!). Valignano most likely gave Yasuke to Nobunaga simply to make it easier for the warlord to let him continue his jesuit mission. Nobunaga did gave Yasuke his name, but nowhere was it ever written he was made a samurai, granted a fief, or even participated in any battles. Even under Nobunaga Yasuke was nothing more than a page (小姓
koshō ). Hell for all we know Yasuke never even spoke japanese. When Nobunaga died Yasuke traveled back to his son Nobutada and guarded him, but one of Mitsuhide Akechi's vassals simply walked to him and had him surrender. Akechi then said "
A black slave is an animal (bestial) and knows nothing, nor is he Japanese, so do not kill him, and place him in the custody at the cathedral of Padre in India ". He wasn't even considered important enough to kill or imprison, he was simply sent back to the jesuits! This is the real Yasuke
As said, it's nice to bend history and romanticize historical figures to tell a cool story, but in the end Yasuke lived and died a slave. He is not someone who should be put on a pedestal to showcase diversity