異性

1. Origins, structure, and basic meaning

• Structure: 異性 is a noun read いせい, referring to a person of a different sex when sexes are being contrasted.
• Basic usage: Use 異性を意識する for becoming conscious of or interested in the other sex and 異性の居住区域 for a residential area designated for people of the other sex.
  • 思春期になると異性を意識する人も増えます。 says that more people become conscious of the opposite sex during adolescence; この寮では異性の居住区域への立ち入りに決まりがあります。 says that the dormitory has rules for entering the residential area of the other sex.

2. Common pitfalls and similar expressions

• 異性を意識する
  • を marks the people of the other sex as the object of awareness.
• 異性の居住区域への立ち入り
  • の identifies whose residential area it is, while への links entry to the destination area.
• 異性 and 同性
  • 異性 refers to a different sex relative to oneself, while 同性 refers to the same sex.