I felt sad for the sister, but angry at the main character. Yes it was a result of the war, his aunt? and the shitty environment, but also his idiocy. Their death was completely in vain just because HE did not like what his aunt did.
I wont only recommend sad shit because there are plenty of lists about that out there.
Manga/Manhwa: Blue Period, A Silent Voice (there's also the movie, but the manga is way better), Nabillera.
Anime: Kobayashi-san Chi no Maid Dragon, K-On, Haibane Renmei, 3gatsu no Lion, Texhnolyze.