This is a guest post from Antonina of OpenBuildings - a community-driven and openly editable encyclopaedia of buildings from around the world. 

They might appear ordinary and overly ascetic on the outside but inside they host unimaginable realms created to meet the exact expectations of their owners. Transparent floors, slides, transforming rooms, and hidden gardens all come into the equation to assist the architects in the challenging task of creating a unique space for their clients in the dense layout of Japanese cities. The setting for these fascinating small jewel-boxes of homes (some are no bigger than 60 sq.m. distributed between two or three stories) is a complex mixture of urban over-population, tight building regulations and proverbially expensive real estate. Yet they all bear a notable understanding for their inhabitants. See more of them HERE.

Junichi Sampei of A.L.X: Living Dancing House

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: Kouichi Torimura

Ryue Nishizawa of SANAA: Moriyama House

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: archi-tokyo.blogspot.com

Shigeru Ban: Curtain Wall House

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: Hiroyuki Hirai

Sou Fujimoto Architects: House N

Jewel Boxes: 10+ Inspired Japanese Private Homesimage:

Iwan Baan www.iwan.com

Tadao Ando: Azuma HouseJewel Boxes: 10+ Inspired Japanese Private Homesimages: Wikipedia user Oiuysdfg; Tadao Ando

Yasuhiro Yamashita/Atelier Tekuto: Cell Brick House

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: Makoto Yoshida

Level Architects: House with  a Slide

Jewel Boxes: 10+ Inspired Japanese Private Homesimages: Level Architects

A.H. Architects: YY House

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: Jérémie Souteyrat

Curiosity: C-1 House

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: Curiosity

K+S: House in Hamadayama

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: Hiroshi Ueda

Sschemata Architecture Office: 63.02° House

Jewel Boxes: 10+ Inspired Japanese Private Homesimage: Takumi Oota