Hongsil Quest

Lee Ye-On, a freshman in the law department, meets her senior Ki Hoon, whom she had a crush on in middle school, by chance in college. On a trip together at Ki Hoon's suggestion, the two receive a strange mission called the 'Hongsil Quest'. 'Hongsil Quest Round 1, 5 cheek kisses!' Lee Ye-On, who was skeptical about her destined partner, gets caught up in the legend of Hongsil, and their relationship flows in an unexpected direction...!

(Source: Bomtoon, translated)