Series Chronology.

From earliest to latest, this is the order in which the Aozora's Adventure games would take place.

1. Aozora's Adventure
2. Aozora's Adventure 64
3. Aozora's Adventure RPG
4. Rock-Aozora
5. Aozora's Adventure II/Rock-Aozora 2
6. Aozora's Adventure Gaiden
7. Aozora's Adventure 3D World
8. Aozora's Adventure III
9. Rock-Aozora 3
10. Aozora's Adventure 64 2

The colors on the titles are to show the three current main story arcs the games take place in.