Toto Books is a secret underground bookstore, accessible to only those with a special key code and pass card to get in. The store is managed by an old man and his pet cat. Their names are never revealed; Yomiko Readman only calls the owner oji-san (literally, "old man"). The bookstore has many old books, meant for those who take their book hunting very seriously.
This is where the adventure begins in Read or Die. Here, Yomiko Readman finds the Immortal Beloved, the book that the I-Jin are looking for. Coincidentally, she also meets her future partner, Nancy Makuhari, here, although they aren't introduced until later.
In R.O.D the TV, Nenene Sumiregawa and the Paper Sisters come here to confront the old man and demand to know where Yomiko is. It is revealed that only he knows Yomiko's hiding place and promised never to tell, but after a plea from Nenene he reveals where she is. Later, Drake Anderson arrives to rescue the group from the Special Operations Division, he's been hired by a mysterious benefactor who only carries the message, "I'm sorry I broke your promise."
Near the end of the series Yomiko Readman, Nancy Makuhari, and Drake Anderson use his bookstore as a place to prepare for the inevitable fight with the British Library. Yomiko takes the last of his books, and the old man says that he's expecting payment.