This looks good and I like the idea but I don't get what the "practice" is here?
this is probably only useful if you've started learning a very small amount of grammar, know hiragana well enough to make furigana useful, and have started memorizing enough kanji/vocab to make 'overheard train chatter' useful. probably, generously, something maybe 3-6 months into your japanese language journey, so not good for bootstrapping.