Charlie...

[aznixiboy]

Hiro's quest to save Charlie has failed... she would die anyways from blood clot on her brain, the best moments or memories of her was the thousand origami cranes, her birthday (April 24) She received the Japanese phrasebook for her birthday from Hiro, and had the almost-late kiss to Hiro ...too sad indeed this was the best episode 10 ("Six Months Ago") for Hiro, I guess this is the last appearance of Charlie R.I.P

[Mrs. Incredible]

Yes, but it was a good lesson for Hiro. When he went back I was wandering what effects his actions would have on the future. Him changing the past and all. It was a good for him to learn that he can not change the past. It's helped him to be more serious about his destiny, and is slowly changing him into the Hiro we saw on the subway. It was good he went back, it gave Charlie a chance to love and let someone close to her before she died. Eventually she was going to die, even if he save her from Sylar. I think they would have made a great couple if she had survived.

[Raivynn]

^
I concur.
This was a valuable lesson for Hiro to learn. He can't save everyone, and Charlies death is going to have a profound effect on him.