隣

The word "tonari" specifically refers to things or people that are adjacent or side-by-side, often sharing a common boundary or being part of a sequence (like seats in a row or houses on a street). It differs from "yoko" (side/horizontal) and "soba" (near/beside) in that it implies a closer, more structured proximity.

While "yoko" describes a general horizontal direction, "tonari" implies that the two objects are of the same kind or category. For example, you would use "tonari" for the house next door, but "yoko" for a bag placed beside a chair.

In casual conversation, "tonari" is frequently used as a shorthand to refer to the person sitting or standing next to the speaker (e.g., "Tonari no hito" becomes just "Tonari").

It is also used in the common idiom "Tonari no shibafu wa aoi" (The grass is greener on the other side), reflecting a psychological state of envy toward others' situations.