Takuma Hasebe is really unlucky! He loses his parents in an accident and his grandparents end up taking care of him. This might be a common tragic story, but it's not over yet! Even worse, his grandparents pass away!
Fortunately, his lawyer informs him that a really nice person wants to adopt him. Of course, he takes up the offer. His new guardian is Grandma Machiyo. He enters Kuregashi School and finds out that Grandma Machiyo is a director at the school!

One day, he asks her, "Why did you adopt me?" but she just says, "Don't worry." Full of anxiety, he ends up being the manager of the school. The job sucks; he's just a janitor!
His busy schedule of school life and managing the school begins...

[From Gamelex]