When Yui was young, his parents were always working. He was lonely and sick of eating the cold food left for him by his mother. His friends would spend their time talking about all the wonderful video games they played, which his own parents never bought for him.

In the midst of his despair, Yui is taken in by a kind man living in the neighborhood. He gives Yui hot food and lets him play all the games he desires—giving him everything his parents cannot. Yui loves his "Nii-chan" more than his parents, friends, or anything else. Nii-chan will continue to let him come over as long as he never tells anyone about him. But his beloved Nii-chan's motives are far from pure, and when things get out of hand, Yui ends up betraying his promise of secrecy.

Six years later, Yui encounters the man once again. With the trauma of his childhood weighing him down, he finds his heart heavy with the regret of running away. He had turned against the man that gave him everything, and with their reunion, Nii-chan is unable to forgive his betrayal. With the hope of understanding the man's actions, Yui starts digging deep into the past.