Mama wa Shougaku 4-nensei

Because her father was sent to London to work, Natsumi, a 4th grade student, also must leave Japan along with him. Her classmates throw a farewell party for her. Natsumi is prepared to go to London, but on the night before Natsumi's arranged departure, a mysterious baby suddenly appears in her house after a roar of thunder! Now Natsumi must balance her impending move with the unexpected responsibility of caring for this mysterious child who has entered her life under strange circumstances.