Yukina is the kind and somewhat innocent twin sister of Hiei—her name literally means "Ice Sprout." As an ice apparition (Kourime), she shares her clan's natural connection to snow and ice, along with some healing abilities. There's also the unusual fact that her tears crystallize into gems, which are incredibly valuable in the human world.
The circumstances of her birth were dark. Yukina's twin brother was considered a forbidden child who should never have existed. When he was born, her clan threw him off a cliff to kill him, ignoring their mother's pleas. For most of the series, Yukina has no idea her brother is even alive—though Hiei shows up periodically to protect her from the shadows, his reasons largely his own. She eventually figures out the truth in the manga, though the English dub leaves more ambiguity about whether her brother survived.
Kuwabara falls for Yukina the moment he sees her on video, dropping everything to come rescue her without even realizing she's Hiei's sister. He's completely devoted to her after that—his strength noticeably spikes whenever she's in danger, as fans noticed during his fight with Risho. He's constantly trying to protect her, though Yukina herself remains oblivious to his feelings. After witnessing how badly Tarukane mistreated her, Kuwabara was genuinely concerned she'd hate all humans. She reassured him that wasn't the case and that she actually likes him, which probably only made things worse for his hopeless crush.
Content compiled by AnimeList.moe from publicly available sources.
