Kazuhiro Kitase spends his nights inside a recurring dream, adventuring across a fantasy world alongside an elf named Mariabelle he's grown close to over the years. When a dragon kills them both mid-dream, Kazuhiro wakes up to find Mariabelle lying next to him in his Tokyo apartment: very real, and still fast asleep. The two now split their time between his ordinary life showing her around modern Japan and the dream world she still calls home.