Fire emblem in a nutshell

I don't get the reference but sounds cool. Upvote!

I'm not sure how to explain this correctly, but i hope this link will help http://i.imgur.com/m3m1GkH.jpg
Cause Corrin/Kamui has to choose a side (Nohr or Hoshido to be exact) and Ryuoma who sorta look like a lobster ask Corrin to come back to hoshido