The language on the note was originally Japanese in the first note, then Elvish when Bullock projects a note in the meeting. It returns to Japanese when Steve puts the elf curse on Stan.
Steve addresses Toshi as Chekov in the baseball stadium. However, Toshi's uniform is blue. In Star Trek (1966), Chekov was always dressed in yellow.
Bullock claims he's never seen the language on the note in the beginning. However, the characters are clearly Japanese in origin.