The heroine Utsunomiya Riyun is the only daughter of Utsunomiya Unizen, the head of Asia's number one financial group, and Carter Williams, the eldest daughter of the Williams family who controls the European economy. She has very high tennis skills and the world's number one female player was defeated by her (when she was 9 years old during the summer vacation). She is not a time traveler, but she is very wise and stupid, and her EQ is a negative number...
In a word: She is not an idiot but a violent and shrewd person, but when she is an idiot and violent and shrewd, she is really not a person...
One more thing... Can't she give some IQ points to that poor EQ? ! (The voices of the above male protagonists...)
This article... Ahem... Don't read if you don't like it...