After moving to Tokyo for university, a young adult man finds that his hopeful new life has become a lonely routine in which he barely speaks to anyone. Then Luisa, a single mother with a young daughter, moves in next door. Watching her struggle to raise her child alone, he cannot help offering small acts of support. Her grateful smile brings color back into his life, and as they share their loneliness, they gradually draw closer in both heart and body. Their peace ends when her violent ex-husband Tatsuro returns. Though fear initially leaves him frozen, seeing Luisa’s tears gives him the courage to stand up and protect her smile.