So you don't want to reincarnate into being Japanese, you want to reincarnate into a nice anime where you have "fun school days" and strange paranormal events. That's fine, but at least be honest with yourself.
I used to idolize Japan too but it seems really messed up, far worse than whatever life you could have in the west.
I'd love to have a comfy life straight out of a slice-of-life anime, just like you so I understand where you're coming from. I think that if you take your life out of grief, though, your soul will be too traumatized to get what you want or something. I dunno, it just sounds risky.
I wish I knew a way for us all to get what we want, but all this "magic" stuff seems way too esoteric to be useful in a practical sense. I know lots of people spend their lives reading books about how to meditate and subtly manifest things but that's not nearly enough when it comes to wanting to shift your reality to be something else but that level of magic seems almost impossible in this world.
Instead I just kind of try to cope in my daily life, regularly imagining myself in a better situation. It keeps me sane as I wait for the day I naturally kick the bucket.
Humans really live far too long huh?