"Dearest" is a song by Ayumi Hamasaki, a Japanese singer and songwriter. The original key of the song is not mentioned, and there is no historical background provided. The song is commonly associated with the manga and anime series "Inuyasha." Ayumi Hamasaki is the interpreter and possibly the composer of the song, though this information is not explicitly stated. No specific curiosity or additional details about the song are mentioned. The melody of "Seu Sorriso - Inuyasha" is not described, leaving it unknown.