The glow up thing is subjective, like maybe they are more attractive when they got older, or when they got dressed up or whatever. Maybe they got a glow up on their personality (if only that was in real life)
For me, I'd say it's this Manhwa, Trapped (Olgami) specifically, Yunsu Park. The artist really improved their style over the series, you can see the massive improvement in the art. (Further proof that a character being attractive largely hinges on the art style)
The pictures attached are him in chapter one, vs him much later in the series.
I wanna know what you guys think!! Let me know!1