Misattribution of arousal, or termed つり橋効果 (read: tsuribashi kouka) is a popular term in Japan used mostly by the youngsters. It describes a process where people falsely assume the feeling of anxiety caused by a thrilling event (i.e. a short bout of fear) as a feeling of affection towards a person. Here you can see the description of it on Wikipedia.
The thrilling events can be anything, i.e. the adrenaline rush when riding roller coasters or the excitement after doing sports. Another common usage of the term is when describing the feeling of anxiety when going to a haunted house in amusement parks. According to the theory, the thrill that a couple experience inside will result in the girl being attracted to the guy or vice versa.
Below is a video of a Fuji TV broadcaster, Midori Matsuo, doing an experiment in Fuji-Q haunted house which is reputedly the scariest haunted house in Japan (they only give you a tiny flashlight to complete the 900m course which takes you an hour to finish). The wacky experiment involves her going inside the haunted house with a guy she has never met before to see whether she would fall for the guy in the end of the course.