Naruto: I Transmigrated Just to Meet You

This is a dual male-lead story, with Obito as the CP (because the protagonist feels that such a kind-hearted boy has suffered too much). The protagonist, Xing Ci, survived for 15 years in the post-apocalyptic world before awakening dual ice- and wood-type abilities. While a large group was out searching for supplies, his home was raided. When he woke up again, he realized he seemed to have transmigrated...

He transmigrated into the Hokage world as Haku. A reminder: the protagonist doesn't know the plot.