For the first time and for the last time

Woo-seok, abandoned by the younger brother he trusted. Yohan, finally feeling relieved. Yeo-ju, who has found someone she likes for the first time. Hyeong-jun, who vehemently opposes his older sister's bullying. Among them, there's someone who sheds tears of happiness for the first time and tears of joy for the last time. Who do you think it is?