- "My head feels bigger than it was, or like the blood is flowing faster... my imagination's freer... and all that's my little secret."
— Yun Sung
This arc, plotted and drawn by Ryan Estrada with dialogue by T Campbell, takes a break from Penny and Aggie's world and follows a few days in the life of Kim Yun Sung, a South Korean teenager whose life, in contrast to that of the American cast, is dominated less by dating and sexual concerns and more by academics. She feels increasingly overwhelmed by school (particularly the subtleties of Mandarin pronunciation) and her mother's constant pressure to do better. One day, she skips school to go hill-climbing, which she finds an exhilarating change of pace. Her best friend Bo-Bae, concerned about her unannounced absence, goes looking for her and gives her hell when she finds her atop the hill. That night in bed, Yun Sung is unconcerned about Bo-Bae's and her mother's failure to understand what she's done, because she's succeeded in expanding her mind beyond the demands of her daily routines and responsibilities.
- Aborted Arc: Campbell initially had plans to tie "Minjung" more closely into the world and themes of Penny and Aggie; however, due to a combination of shifting priorities for the comic and a mostly lackluster fan response to the arc, he chose not to do any further Yun Sung stories. She does get a brief but significant appearance in the strip's epilogue, Six Septembers Later, as Duane's significant other.
- Celeb Crush: Yun Sung has one on Shia LaBeouf and uses him as an imaginary confidant.
- Education Mama: Yun Sung's mother chides her for her grades slipping almost five percent from the previous quarter. She disregards her daughter's explanation that her course load has increased from fifteen to eighteen classes and says she should be happy her mother wants to save her from "a life of scrubbing toilets and sleeping in them."
- Ghibli Hills: The quiet hilltop to which Yun Sung escapes.