Sapphie's Secret! Yay! is episode 4 of Jewelpet Sunshine. It first aired on April 30, 2011.
Sapphie has a passion for the cosmos and has built a secret laboratory on campus to build herself a rocket. However, her cover is blown when her helper Nejikawa steals Kanon's beauty mask for an experiment.
- This is the first full-length episode of the season.