How do you unlock the seven treasures mission in pokemon explorers of sky?

1. Recruit Kecleon, who joins your team after the Spinda Café storyline as part of the guild story.

2. Complete the main storyline. At certain plot points (e.g. reaching Purity Forest), Kecleon will give you more of the Seven Wonders missions. When you first recruitKecleon he gives you his mission to reach Mt. Freeze.