Temporary Guardian

At the request of an old friend, the protagonist goes to Japan to look after a thirteen-year-old girl! Although the girl has a prickly personality and is extremely hard to like, it seems like a simple enough job. He only has to look after a child for a month. How difficult could it be? But then all sorts of strange things start happening. The protagonist never expected that merely acting as a temporary guardian would drag him into a great disaster that took place 65 million years ago. Life really is full of surprises!