반오십

'Ban-o-sip' began to gain significant popularity from the mid-to-late 2010s. Even before that, it was sometimes used on university campuses as a lighthearted way to tease close seniors who were about to graduate or were late returning from military service. In 2014, the term 'Ban-o-sip' gained further attention as 25-year-old idol members like AOA's Choa and EXO's Xiumin were actively promoting in the entertainment industry. However, since 2023, its usage has significantly decreased due to a stronger trend of using birth years instead of age, and it is gradually becoming obsolete.

'Ban-o-sip' is a Korean expression meaning '25 years old'. It originated from the fact that half of 50 is 25. It primarily refers to 25 years old by Korean age, which corresponds to 24 years old by 'yeon-nai' (calendar age) or 23-24 years old by international age.

This expression is used to lightly convey the bittersweet feeling of starting to get old, or to playfully tease someone who is 25, implying they are older than they actually are. It is also used when one feels sentimental about having become an adult, or, rarely, to assert one's age as a form of authority. Its usage is a complex interplay of regret that the prime of life, the twenties, is already halfway over, and the realization that after the peak of the early to mid-twenties, one must now firmly establish oneself as a member of society. The fact that the Youth Basic Act defines 'youth' only up to age 24, and that one is no longer considered a youth from age 25, also reinforces the perception associated with this age.

Pronounced as 'Ban-oh-ship' ([ban.o.ɕip]).

Primarily used by university students and young professionals in their early to mid-twenties. It was especially common for 25-year-olds themselves to express their feelings about their age, or for peers to playfully tease each other. It was also used among fans when 25-year-old idol members were mentioned in the entertainment industry. The expression was widely used by both men and women.

• "Already Ban-o-sip, time really flies!"
• "Hey, if you're Ban-o-sip, you should grow up a bit!"
• "Shall we go on a trip to celebrate Ban-o-sip?"
• "Perhaps because I'm in my final year of university, the term Ban-o-sip resonates more with me."