Tensai Ikkyuu

Ikkyuu Tensai is a fiercely self-assured young detective who arrives on Nanaeshima in pursuit of the legendary "Triple Seven Treasure." Blessed with extraordinary deductive reasoning and an uncanny talent for solving puzzles, she nevertheless struggles to connect with others due to her haughty demeanor—a flaw that Yashiro Shigeru bluntly describes as a "broken personality." Viewing Shigeru as a worthy rival she cannot afford to ignore, Ikkyuu repeatedly demonstrates her sharp perceptiveness and brilliant problem-solving skills throughout their treasure-hunting adventures.