The Japanese noun '恋 (こい)' refers to romantic love or being in love. It specifically describes the deep emotional attachment or affection one feels towards another person, often with a focus on the passionate or longing aspects of love. This term is commonly used in contexts involving romantic relationships, crushes, or unrequited love. For example: I am in love with her「彼女に恋をしている」(かのじょにこいをしている). This is a love song「これは恋の歌です」(これはこいのうたです). Note that '恋' is distinct from other types of love, such as familial love (愛, あい), and often carries a sense of yearning or desire.