Fusae Campbell Kinoshita is Agasa Hakase's long lost love and an accessory fashion designer with a ginkgo leaf-themed brand.

Fusae Campbell is of Japanese-American descent and has the unusual feature (for a Japanese) of blond hair. Feeling self-conscious about this (presumably aided by some teasing from intolerant schoolmates), she became very timid and came to wear a low hat to cover her hair.

When she was in fourth grade, Fusae met Agasa Hiroshi, who helped her overcome her timidness. The two became very fond of each other, especially since Agasa did not ridicule her for her hair color, but Fusae soon had to move away before she could confess her feelings for him. In a letter she left, she promised that once every ten years she would wait for Agasa at "the place of memories" (the ginkgo trees behind Teitan elementary school) until he met up with her, but the hints she left were too complicated for Agasa to crack, and it was not until 40 years later the two were finally reunited with the help of the Detective Boys. By that time Fusae had become a successful fashion designer, with a ginkgo leaf being her trademark signature (because Agasa had commented on her hair looking like ginkgo leaves in the fall).

While the two parted inconclusively because of mistaken conceptions about the other, they did recognize each other, and Agasa was able to make his feelings known to her. Whether the two will meet anytime soon remains to be seen.

She has one foreign English speaking parent. Her stepdad has a friend named Billy whose wife likes the ginkgo leaf themed purses Fusae designs.

Fusae has a kind and caring personality, evidenced when she loaned Ran her umbrella while waiting for Agasa ten years prior to the current timeline.