The old mansion on Prinsengracht embankment at different times served as a residential building, a warehouse, and an industrial building. Here, the head of the family Otto Frank worked at the jam additives company. With the help of his colleagues, he arranged a hiding place, the only passage into which was blocked by a bookcase. Soon, four more people joined the Frank family. It was cramped in the room, people must not make noise and go outside, because the company continued to work outside the walls. Sympathizers provided residents with food, books and news about the outside world. To somehow brighten up the days in closure, Anne began to keep her diary, which her father gave her for her thirteen's birthday. The girl addresses her notes to her fictional friend Kitty.