Lin's friend, Airi, is being stalked. The three brothers immediately come to her aid, saying they'll take care of the stalker. They sneakily follow Airi around and soon find out it's not just a stalker that follows Airi around...
Stalkers are creepy guys who show up 
everywhere you go and follow you around.
Los acosadores te siguen a 
donde vayas y son muy raros.
Los acosadores son unos tíos muy raros que te siguen vayas donde vayas.
Stalkers são caras estranhos que 
ficam te seguindo aonde você for.