階

• Reading: かい
• Romaji: kai
• Kanji breakdown: 階 (kai) — 阝 (hill) + 皆 (all); staircase, floor level
• Pronunciation: /ka.i/

Meaning

Storey; story; floor. Used to indicate which level of a building something is on.

Used both as a standalone noun and as a counter suffix for building floors. Japanese counting starts with 一階 (いっかい, first floor/ground floor). Unlike British English where the ground floor is separate from the first floor, Japanese 一階 corresponds to the ground level. Counting: 一階 (いっかい), 二階 (にかい), 三階 (さんがい — irregular reading).

Examples

1. トイレは二階にあります。 The restroom is on the second floor.
2. このビルは十階建てです。 This building is ten stories tall.
3. 三階のレストランで食べましょう。 Let's eat at the restaurant on the third floor.

Usage Guide

Context: buildings, directions, shopping

Tone: neutral

Origin & History

The kanji 階 combines 阝 (hill/mound radical) and 皆 (all/everyone), originally meaning steps or a staircase ascending a hill. The meaning extended to floors of a building.

Cultural Context

Era: Ancient

Generation: All ages

Social background: Universal