Koyuki Hakogawa, a student at Ouratani University, participated in a part-time job with her friends. For one month, one million yen for doing nothing. However, she must live with a switch that, if pressed, will destroy a happy family. - Title: Switch - Author: Ken Seya - Publisher: Kodansha - ISBN: 9784065293379 The condition is good as I have only read it once. Thank you for looking.