Harumi Ogame (HIGA Manami), who works at a foreign IT company in Tokyo, receives news that her mother, Mitsuyo (ISHINO Mako), has passed away. Due to a feud with her father, Sentaro (MIURA Tomokazu), Harumi had no intention of ever returning to her hometown. However, a postcard she received from her mother before her death bothers her, so she decides to return to her hometown for the first time in a while.
While attending her mother's wake, Ogame family's eldest daughter, Tamako (MATSUOKA Egatomi), second daughter, Hamako (YAMAZAI Shizuyo), and Harumi are talking with their father, Sentaro, when lawyer Ryunosuke Jojima (MIURA Shohei) appears and says, "From now on, we will protect your father's health and property."
Tamako and Hamako are shocked though they are the ones to report to the family court that Sentaro has dementia. Ryunosuke, who was managing Ogame family's property, finds that Sentaro is hiding a legendary pearl worth 600 million yen. Ryunosuke desperately searches for the legendary pearl because he can get a huge additional reward if he sells it. Meanwhile, Harumi cannot forgive her father for causing her mother's death due to hard work of pearl farming, So she indulges in memories with her mother all alone.
Meanwhile, Tamako and Hamako, who are aiming for their father's inheritance, accidentally find the existence of that pearl and try to find before Ryunosuke does. Where on earth is the legendary pearl hidden? What is the surprising truth that Harumi and her family reach in the end of the turmoil surrounding the treasure?
