zakiwana guide - entrance to the castle

you find the entrance to the castle, and it asks you for a password. you don't know the password, so you're done for. now you might have noticed that you got a strange item with text on it during the mansion. zaki realizes she still has this item, which means that everything she assumed to be a bad dream, was in fact not

zaki starts to hear hanako's voice, the girl she supposedly killed in her "dream". hanako will help zaki on figuring out the password. every 5 minutes she will provide a hint, and after several hints she will give the answer to the puzzle. to properly explain the solution, here's an image of the item with all the hints unlocked:

the red characters spell 咲いた咲いた, and it reads like saita saita. this has one connection in particular which is the background music. if you listen to the music closely, you'll hear miku singing saita saita, the exact same phrase as mentioned

notice how she's singing those lyrics, and then try to find a music-related element in the image. you'll realize the letters are actually musical notes. if we take a closer listen, we can certainly say miku is singing each syllable in these notes:

this explains the letters at the bottom of the red text, but what about the ones at the left? well, for each column you need to pick the japanese character that matches both the letter at the left and the one at the bottom. by doing so, you'll get this piece of text:

鬼の目にも涙

use this as the password, and you will be granted access to the castle