Kenji is surprised when the most popular girl in school invites him to her family's home for a weekend in the summer. He finds it awkward to fit in with her large and affluent family, especially since Natsuki is pretending that he is her fiancée! Kenji receives a work email from OZ, an online virtual world where he has some part-time work doing web maintenance. The email contains a code to be solved, and Kenji loves math puzzles. He solves the code and sends in the answer. The next morning, Kenji discovers that he has unwittingly unleashed a terrible danger into OZ.

I really enjoyed this manga! Now that I have read it, I want to watch the anime. The plot is a very interesting mix of real life and online life. The way that the two realities intertwine and affect each other is very complex, especially since some of the characters think the online OZ is just a game they can't understand, something for the young people to waste their time on. There is a beautiful storyline about the different generations learning to understand each other better and appreciate the strength and knowledge that they all bring to the table. They learn to value each other.

I liked Kenji's character and the way that he finds courage and inspiration with Natsuki's family. They really encourage each other to be the best version of themselves. It's beautiful the way the whole family pulls together during difficult times, and they include Kenji and welcome him. He is determined to live up to their trust in him, and it makes him very strong.

Natsuki is sort of foolish in the beginning, pretending to have a fiancée, doting on her dead-beat uncle, and generally being aimless in life. But through the story, she realizes that she has to grow up and find her true purpose. She really wants to make a difference in the world, and she finds that inner strength.