Lucca

    Lucca is Crono's best friend. She loves science and uses her knowledge to build fantastic machines and very clever weapons. She's the one who invented the Telepod which triggered Marle's pendant to open a time gate. She then created a "Gate Key" to open  the time gates on their free will whenever they encounter one. 
      During the adventure she eventually became a master of a robot (Robo) they found in the future and also found a time portal which leads to a sad past. 
     She went back to the time her mother had an accident and was pinned in one of the machines her father had invented. Lucca, as a little girl, was there and saw her mother pinned down and was helpless to save her. Since that time, Lucca studied machines to prevent another accident from occurring. Her mother couldn't walk anymore and Lucca blames herself for it.
     Now, she has a chance to change history. Lucca saved her mother by pressing the right codes to stop the machine and went home in her time to find her robot waiting patiently for her and gave her a gift: the Greendream. She realized that machines aren't that bad at all now that she found a friend like Robo. Lucca helped Crono with his journey to stop Lavos so she could preserve the knowledge and science of the world she so loved.
      She also learns Fire Magic during the adventure.