Here are a few PPTs for Lesson 1 (Great for both 3rd and 4th grade). My co-teacher gave me the first. The second I adapted from a "hidden slide" PPT based on the old text book. They are designed to introduce/familarize students with the new YBM-Si-sa characters. Great for both 3rd and 4th grade.
The first is just a simple Intro to the characters.
The second is a hidden slide, guess the character activity
I've also included a song, "Hello. How Are You?", with some cute dancing penguins (I think they're penguins

). My students enjoyed the song and it uses the target language.