PURPOSE: To comfortably sit on a chair with keeping the shape of obi (sash) for kimono by providing the backrest with a recess for housing otaiko (drum knot of obi).

CONSTITUTION: A woman L is wearing kimono and fastening a drum knot 7 of obi for kimono round her waist. A chair 1 comprises a backrest 2, a seat 3 and legs 4. A recess 5 is formed on front surface of the backrest 2 having the thickness of 25cm. The drum knot 7 having the thickness of 18cm is fitted in the recess 5. The recess 5 is sized 30cm by 30cm. The substantial center part of the recess 5 is 60cm high. The waist position of woman L being 60cm high and the size of the drum knot 7 of obi being 28cm by 28cm, the drum knot 7 of obi is adapted to fit in the recess 5. The position of recess 5 is at the average height of waist, the size of recess 5 is in the extent of the drum knot 7 of obi for kimono, and the depth of recess 5 is in the extent of the drum knot 7 of obi for kimono thereby the chair 1 is convenient especially for the woman L wearing kimono.