Enter Geo. Go to Kristie's place and talk to Niccolo and Kristie.
Enter Polpota Harbor and go to the beach to pick up Niccolo.
Enter Geo and head to Kristie's again.
Enter Gato Grottoes and go to the western point on the map. Choose to go behind the Waterfall. Go to the Bird's Nest so Niccolo can get some leaves.
Enter Geo and go Kristie's again.
Enter Gato Grottoes again and go to the Bird's Nest again. Niccolo will fall down.
Enter Polpota Harbor and pick up Niccolo again. Niccolo's journey has now come to an end.
Upon Completion: Return home, talk to Lil' Cactus, go downstairs (watch him write the Event on the leaf), and go back upstairs to save your game before continuing.