I’m a corporate employee trapped in a grueling black company. One day, as usual, I worked overtime and returned home at 3:00 in the morning, utterly drained from the excessive workload. Without even changing out of my suit, I headed straight to bed and fell asleep instantly. …And then, I remember… “Where am I?” Just like the tale of Taro Urashima, I had saved a turtle and was led to Ryugu Castle. To my surprise, my ex-girlfriend, Hiyori, who was supposed to have passed away a few years ago, was inexplicably there.