Yaichi is a work-at-home suburban dad in contemporary Tokyo; formerly married to Natsuki, and father to their young daughter, Kana. Their lives suddenly change with the arrival at their doorstep of a hulking, affable Canadian named Mike Flanagan, who declares himself to be the widower of Yaichi's estranged gay twin, Ryoji. Mike is on a quest to explore Ryoji's past, and the family reluctantly but dutifully takes him in. What follows is an unprecedented and heartbreaking look at the state of a largely still-closeted Japanese gay culture: how it's been affected by the West, and how the next generation can change the preconceptions about it and prejudices against it.

As Mike continues his journey of discovery concerning Ryoji's past, Yaichi gradually comes to understand that being gay is just another way of being human. And that, in many ways, remains a radical concept in Japan even today. In the meantime, the bond between Mike and young Kana grows ever stronger, and yet he is going to have to return to Canada soon—a fact that fills them both with impending heartbreak. But not before more than a few revelations come to light.