Yoona & Donghae are Childhood friend, so Yoona and Donghae sharing there problems and helping with each other.. Donghae promise to Yoona that don't ever leave him and Yoona agree with it.. But after a month Donghae told Yoona that he need to go to America and need to continue his schooling there.. So Yoona is so upset that Donghae broke his promise that don't leave each other.. After a year Donghae came back at Korea, and Taeyeon (Yoona's Friend) invite her other friends that she have a night party at her house, during the party, Yoona and Donghae bumped with each other, Donghae was so happy but Yoona was still upset with him, after a week Yoona and Donghae had a same school and had a same class..

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what do you think happen in next chapter?