Uhhh ... she COULD have asked his friend to tell him she was looking for him or asked for his number. Yeah, I know Japanese etiquette says that would but outside of social norms and an intrusion but you didn't get his number when you went to view the fireworks so ... that's your bad. When she sees him she HAS to ask for his number, and address, and birth sign. That way she can be a proper stalker.
Also, I've never had a good/cute stalker so I don't think they exist. Stalkers are always some jacked-up (aka ugly and often out of shape) person that you would never find attractive. If you found them attractive they wouldn't have to stalk you and you would want to be around them too.