Although this review is thought mostly as a brief analisis of Hitomi's character development, from this point onwards this review can contain some minor spoilers to the argument, so if you haven't seen the show and wants to do it I reccommend to stop reading here.
Getting back to it, as I said before, this show is a really direct metaphore about a person, in this case Hitomi, suffering from depresion and as that, it is a really good aproach to this mental health illnes as it doesn't depicts it as that caricature of said illness we're somewhat used to get when an anime treats this subject: Hitomi is a functional girl, she carries on with his regular activities and ordinary high school student life, that being said, our focal point to read his depresion is not her being unable to do things, instead, it will be how she still lives even when she thinks she doesn't have a reason to.
She's completely lost her will, she thinks she's the sole culprit of her current state, she can't see any good in herself and therefore, she things she doesn't have any colors in his life. The colors have gone because she can't see them in herself, if you can't love yourself, you can't see the good things in your environment. And that's a really good description of how a person going through a depresive state does feel. Not all people in that situation wants to die, someones just doesn't have the will to live neither to die, and that's where Hitomi's at the start of the show.
From this point, Irozuku Sekai no Ashita kara teachs us how important can be to have peopla that genuinely cares about us and how their help can't cure us at all, but can be the starting point to heal we can't find for ourselves. That's where Kohaku, Hitomi's grandmother comes into action, she'll be the one to ignite Hitomi's spark and help her take that first step to recover the colors of the world, to be again able to see the bright side of things and the bright side of herself, to forgive herself and finally understand she's been unfairly chargin herself with the wrong guilt of being born a magician, something she simply mustn't feel guilty about at all. Thanks to the present and past Kohaku and the whole cast, she'll recover the set of emotions she's lost, she'll get rid of the rigid herself she's forged through years of suffering and will learn, through loving others, to love herself.
Irozuku Sekai no Ashira kara is a beautiful journey to know yourself better and get through hard times. Sometimes you won't be able to do it by yourself, but there's always someone, even if we can't see them, that worries about us and would do anything to help us heal. You've lost your colors? Not forever. You can't get to see the good things in yourself? There's always people that can see them and tell you how they look, eventually, you'll be able to see them by yourself.
