While Conan was helping FBI in Haido Central Hospital, he was seen by a student from Ran's school. This student is called Nakamichi, and he has appeared before when the real Dr Araide Came back. Nakamichi has been up till this point just a minor character. Will he continue to remain as minor character after this event? I doubt that.

There are two possible scenarios:

1) Since Eisuke has nothing to do after finding Mizunashi Rena, he will probably disappear suddenly, just like he appeared suddenly. If they start to talk about his disappearance at the School, and about his last call from Haido Central Hospital, then maybe Nakamichi will mention that he saw Conan there!

2) There's a probability that the one Conan saw is a person disguised as Nakamichi. The reason is that Nakamichi must be living somewhere around Beika so that he can go to Teitan high school. We all know that Beika has a hospital, in fact Conan himself was hospitalized there once. So it's strange for someone living in Beika to go to a hospital far away from his home.