Ruddy Cheeks

Eun-San and Hae-Gyeong, who have known each other since childhood, begin to hold each other in childhood memories after Hae-Gyeong's manifestation. Yun-San, who has now manifested as an omega, accidentally reunites with Hae-Gyeong at an amusement park and continues to secretly communicate with him without the adults knowing. After a time when they felt each other through messenger messages and pheromones on clothes due to the pheromones of their still-imperfect adolescence, the two, now fully grown adults, meet again on Jeju Island...!

(Source: Ridibooks, translated)