To get to the bottom of something would mean that their is something mysterious going on, and that person wants to know everything about it as soon as possible. Its like saying that you would like to 'crack a code', or solve the case.
Answer:
The story is told in the third-person-limited point of view; the narrator is not a character in the story, but he is privy to the thoughts of one character.
A tanka poem has 5 lines. It consists of 31 syllables. I hope this helps.