If you press the button, you will be locked in with that child you hate for five years.

"Press this button and you'll get one million yen—but you'll be confined for five years—also..." Tsukimori Shizue pressed the button without listening to the rest of the warning, on a whim. She was transported to a pure white space. And worse, she ended up with Yayoi Kagami, the person she hated most in her life. She regretted it, but it was too late. Days filled with insults and silence, a relationship that held nothing but hatred—yet time relentlessly continued to shake its foundation. And as they continued to pour out their feelings to each other, their relationship began to change in unexpected ways...?