Ryûhei Tsutsui

What happens, when an ordinary family in one of the arguably most advanced cities in the world starts living in two different worlds? What happens, when that fine line between reality and fantasy begins to blur, when a computer game controls the space you live in, re-defines your real life? When a gigantic, green iguana is the only one that can see, how the people around it slowly lose themselves between these different worlds?

A brother and sister learn their biological grandfather was a kamikaze pilot who died during World War II. During their research into his life, they get conflicting accounts from his former comrades about his character and how he joined his squadron.