A documentary anime retelling the shipwreck of the freight boat Tsushima Maru, which was carrying 836 schoolchildren home in July 1944 when it was attacked and sunk by an American submarine. Produced by the surviving family members of the Tsushima Maru.

Cheerful Mimiko has a wonderfully strange family—a Panda for her Papa; and his son Panny, calls her Mom! When Panny follows Mimiko to school, he must pretend to be a teddy bear so Mimiko won't get into trouble. Despite his efforts to behave, Panny causes trouble in school and now the school is after Panny! Then, Panny makes a new friend, Tiny, a baby tiger who's wandered off from the circus.