Super nice game it made me really happy to play and read through! The only thing I noticed that was off is generally nonogram games don't grey out the numbers until the player has solved to one of the edges (so for instance, the 111 column in the center of the lesson 5 screenshot would normally not grey out the middle 1 until the squares to the previous box are X'd out since there are still squares that *could* be marked between those two filled in squares, even if they're not ultimately the correct answer)
It's not a huge deal but it did make some of the later puzzles easier to solve since the player is given that information. Regardless, it's a solid little game with a cute story and I enjoyed it a lot. Great job Nami!