Haiyuan Ai and Conan confessed in episode 156. The title of this episode is the first part of the crime love story in this hall. In this episode, Haiyuan loves to express his love for Conan clearly with the lines rehearsed by the juvenile detective team, but Conan still doesn't notice it. Although Haiyuan Ai expressed her love for Conan many times in the whole story, it is rather obscure, and the word "falling in love with you" is really only used this time.
Haiyuan Ai and Conan are the two closest people in the play, because their circumstances are almost the same. They are both close friends and good partners in solving crimes. It can be said that Conan is better than Haiyuan in IQ, but far worse than this bold girl in EQ, which is also very common in Japanese cartoons.
In the process of their communication, Haiyuan Ai has repeatedly expressed her love for Conan, for example, she said that Conan should always accompany her and so on. These are all implicit expressions, but Conan, who is worried about emotional intelligence, has been unable to understand her thoughts. Even in episode 156, Haiyuan Ai has clearly expressed his feelings for him with lines, but Conan didn't notice these.
From an adult to a child's world, Haiyuan Ai is more mature as a girl than Conan, but Conan's emotional blank is more suitable for a child's identity. The development of the plot still needs Conan to be a child, so his feelings can't be greatly developed.