One sunny day, a young boy named Jo Kang meets a curious young girl dressed in a bright yellow raincoat. She tells everyone in school that she is an alien and whomever she touches or gets touched will be harmed. Everyone in that school gets afraid of her except Jo Kang. Jo Kang befriends the girl, Ari, and falls instantly in love with her. Ari starts telling stories to Jo and he believes everything she says. He did everything for her. One rainy day Jo and Ari stays together in the yellow raincoat and instantly he gets affected by Measles. Soon afterward, she disappears.

Ten years later, Ari contacts Jo Kang, now in high school, and asks to meet again. Although they have not seen each other in a decade, they have a wonderful time together, and their love begins anew. Ari tells that there are hot springs in her temple and the mountain is a volcano. Ari and Jo have a good time between them. Ari continues telling stories to Jo. She says her English got better by getting trained from an English ghost that visits her when she is naked, Jo believes her. She also tells him that she wil marry a banker so that she will rob the bank to get money and leave the planet. Jo brings Ari her favourite dish from his home travelling the whole night and presenting to her as a surprise next morning. She kisses her and Jo gets affected by Flu. But then, Ari disappears once more, leaving Jo Kang devastated.

Jo Kang waited a very long time for Ari and One day Ari appears in front of him and tells him to come with her. Since he was busy he tied a shoelace in her leg along with the chair. Later that evening they have a good time in Jo's home and Ari explains to Jo's father that people from NASA kidnapped her since the magnetic force in her body attracts the UFO's. Then Jo plans for the next day but Ari tells him that she is leaving for the states. While leaving Ari tells Jo not to cross the line design which Ari asks him usually from her childhood.

Jo's friend gets stuck in an accident and gets admitted to the hospital. When Jo visits him his friend see Ari. With Pain and confusion Jo visits to Ari's Uncle (The Priest) with a fuel can and pours over himself seeking explanation. He discovers that Ari is suffering from AIDS that has been accidentally transmitted in the hospital during her child hood accident where her father dies.

He then visits the Photo Exhibition conducted by Ari. Ari looks him next to her portrait and tells him that "You two look beautiful!" and Jo explains that She is Ari type. Then he Piggy bags Ari to a lawn where she explains that lawn design is sign left by an UFO. Later that night Ari fells sick and is admitted back in the hospital. Jo stands outside the Hospital wetting himself in the rain. The Priest (Ari's Uncle) asks him to come inside. Jo tells him that Ari would love seeing him standing behind the floor line.

Jo designs a sign said to be left by an UFO in a grass field in order to fulfill Ari's destiny to leave the planet (which he believed). Then He brings Ari to the lawn illegally from the hospital. Ari passing her last moments of her life feels pity and love on Jo that he believed everything she said. At last the signs of Flying saucer arrival is shown as a mark of resemblance of Ari passing away.

In the final scene Jo explains us the Aroma of love left by Ari and still believes that she lives in another planet waiting that he will meet her one day.