XenoGear: Chrono Cross Over

[Quto]

In the game Xenogears for the PlayStation 1;
Lucca from Chrono trigger makes a cameo appearance in Lahan Village, the first village you begin your game in and explore freely.
If you speak with her, she acts as the tutorial on how to save and explains where you can save your game in Xenogears.

This is a small surprise since they both Xenogears and Chrono Trigger were owned by Square Soft before merging with Enix to become Square Enix.

Source
http://chrono.wikia.com/wiki/Lucca

https://encrypted-tbn1.gstatic.com/image...HD1XIWDxRp