Pure Love summary:

Since his childhood, he has only been chasing Sooyi’s back. Sooyi kept trying to reject him under the pretext that he was too young for her, but she was the only woman for him. However, Sooyi got married during his military service… “I’ll bet my whole life on it and show my love to my noona,” Sooyi is colored with the hot love of a younger man without knowing why.