Monster Rancher DS/Walkthrough

You are a new initiate of BOMBA, the Borgan Monster Battle Academy. After giving your name and picking a name for your ranch, Sapphire welcomes you and starts to tell you about the highly efficient, well-trained breeding assistants all initiates get. She is interrupted by a scream for help, and the person doing the yelling crashes into the building. Upon finding out where she is, she introduces herself as Cleo, and insists that she'd make a good breeding assistant.

Electra, the president of BOMBA, arrives and impressed by Cleo's attitude, assigns her as your breeding assistant and sends you on your way to generate a monster.