A Journey to Another World That Began Out of Nowhere

As an ordinary person, why is the little sister I picked up as a child a goddess? Why does my childhood friend want to chop me up? And why have I reincarnated in another world?! None of this makes any sense...

(Note: This is a practice piece, so it's just for practice! If I don't work hard, how can I succeed? I believe I can definitely improve my writing. Yeah! That's right!)