The Phone Box at the Edge of the World by Laura Imai Messina
When you have lost everything, what will you find? When Yui loses her mother and daughter in the tsunami, she wonders how she will ever carry on. Yet, in the face of this unthinkable loss, life must somehow continue. Then one day she hears about a widower who has an old disused telephone box in his garden. There the old man finds the strength to speak to his late wife and begin to come to terms with his grief.
As news of the phone box spreads, people from miles around will travel there to connect with their own lost loved ones. Soon Yui will make a pilgrimage to the phone box, too. But once there she cannot bring herself to speak into the receiver. Then she finds Takeshi, a bereaved husband whose own daughter has stopped talking in the wake of their loss.
What happens next will warm your heart, even when it feels as though it is breaking . . .