It’s a reference to a popular anime called “your lie in April” when the song in Japanese is translated into English it says “ It was you, it was you! The one who made me realize if we can make even the darkness shine, it will become a starry sky.” If somebody says this to you, please treat them nicely. They really like spending time with you.

(noun) A successful type of theft which results in an acceptable, impressive and rewarding payday for the protagonist.