Hello Dulcamara !!
Thank you very much for your kind guidance!!
I went to the office, read the journal and wrote all the necessary pages on paper.
And I pasted all those sentences in my document and translated it to Japanese by web.
I thought about the whole two days.
I searched through all the areas allowed by Elodea.
I swam a lot in the sea.
I also explored in the ship.
However, I could not find a useful thing as a clue to the puzzle.
I will ask you again.
There are six stone knobs to be found first.
However, there are seven in the journal.
Perhaps, should I find another hidden knob?
Or is there somewhere to show how to turn six knobs?
I'm really sorry for the repeated question.