The song “Koibito yo,” by the female Japanese singer songwriter ITSUWA Mayumi, sold a million copies after it was released in 1980. In 1985 the song “Aijinn” sung in Japanese by the female Taiwanese singer Teresa TEN – who was also popular in Japan – also sold a million copies. Both songs expressed a woman’s feelings towards the man she loves, but koibito and aijinn are completely different. An appropriate English translation of koi might be “romance” and of ai “love.” Koibito refers to a partner of the opposite sex, who makes your heart throb when you see them and as such is somebody you are seeing with a view to marriage. On the other hand, ai refers to the absolute affection you might also feel for members of your family. This is why many women are named “Ai” or have this character as part of their name. However, aijinn, in which jin or hito (person) is added after ai, means a person of the opposite sex who is married. In short, it is a lover who is committing adultery. If you combine the kanji for koi and ai you get the word “rennai.” This may be taken to mean romance with affection, but in fact it is generally used in the same way as koi. These days the term koibito is not often used, indeed, a male partner is casually called “kare / kareshi” and a female partner “kanojo.” You can say “sukina hito” to refer to someone you have romantic feelings towards, regardless of whether that person reciprocates your affection.