Otouto

Set in the 1900s, it tells the story of Hekiro, younger brother, a high-strung and gifted, weak yet stubborn misfit student, and his sister, Gen.
The young woman takes on the role of parent (eventually becomes Hekiro's surrogate mother) and takes care of her brother until his premature death from consumption.
(Source: Wikipedia, DramaWiki)
~~ Adapted from the novel "Otouto" (おとうと) by Koda Aya (幸田文).