After the final bell of the school year, class president Kim Sunoo looks forward to a quiet summer - no meetings, no deadlines, and especially no Riki Nishimura, the playful troublemaker who never stops teasing him. But luck isn't on his side. When the whole class flies to Los Angeles for a summer trip, Sunoo finds himself stuck with the one person he swore to avoid. Between lost schedules, late-night talks, and too many moments that feel almost like fate, Sunoo begins to realize that maybe Riki isn't as careless as he seems. From hallway rivals to summer companions, two boys learn that sometimes, hate is just the beginning of something else - something they can't quite name under the same sky.