With Miyamoto's projects revolving around vicious plumbers setting fire to turtles and elves slaying demons, he need cutesy.
Whilst the main inspiration behind the much loved GameCube hit Pikmin was the designer's love of gardening and possibly using his creations to fuel his ideas, according to Kotaku he had a faily large proportion of Japan in mind - Japanese schoolgirls.
Every once in a while, you want to make something that high school girls can get into...
An advert around the 2001 release of the first game even featured "Love Song" as its backing track.