4 ideas
After Eriko is murdered, Mikage is away on a work trip. She eats a katsudon so good at a late-night diner that she orders a second one to go, takes a long taxi ride to the town where Yuichi is staying alone, and climbs onto a roof to reach his inn window. She hands him the still-warm food as a way of refusing to let him disappear into grief. Their bond is sealed not by a declaration but by carrying a meal a great distance at night.
After her grandmother, her last relative, dies, Mikage can sleep only beside the refrigerator, where the machine's steady hum and the kitchen's ordinary objects give her the stability the empty apartment cannot. The kitchen is the one room whose purpose continues regardless of who has died. That makes it a reliable place for a person whose sense of continuity has been broken.
The Tanabe household is built out of loss. Yuichi's father became Eriko, a woman, after his wife died, and the household then takes in the newly orphaned Mikage on the strength of a slight acquaintance. The book argues that people stripped of blood family can form a real household through shared rooms, shared meals, and unforced hospitality, and that nobody has to name what the household is for it to work.
Mikage works through grief by cooking obsessively. She remakes dishes until she masters them, then becomes a cooking teacher's assistant, so that repetitive, bodily, skill-building work gives her a path back into life that thinking about the loss cannot. Seen this way, whether a bereaved person can taste, cook, and feed others becomes the measure of whether they are returning to the living.