Knock!Knock! - Kaori Takahashi

?Where's my bear?” asks a little girl as soon as she comes home from school. But... he's missing! Where could he be? So she sets off to find him, knocking on the door of each apartment in her building. As she climbs higher and higher, she meets all kinds of people, makes a lot of new friends, and sees some strange sights? but what about her bear? Will she find him?
A child's quest turns into a wonderful adventure that literally unfolds, step by step, into a building full of life. Knock! Knock! is book architecture at its inspired best.