Pino is a child monster, and is the younger sister of Puku. She is usually very shy on approach, and is very friendly.
Parin first saw Pino when she first came to town because of her parents going abroad. As she walked throught the town Plaza, getting used to her new surroundings, she saw Pino at the end of the street, being chased by Puchi.
When all hope seemed lost, Parin swooped in and saved the day. This is how they became friends. The introduced themselves to each other, but to the adults' confusion, as they could not see Monsters, and all they saw was Parin talking to herself, which Pamela assumes to be just playing.
As a thank you for saving her, Pino shows Parin a hole through the walls on the other side of town. This led through a mysterious portal into Monster village.