I have discovered what I call the Shounen-Bishounen Effect: In a long running series, as the art improves, the main character will become more and more of a bishounen over time.
Examples include: Kamijou Touma and Accelerator from To Aru Majutsu no Index, Kurosaki Ichigo from Bleach, and Negi Springfield from Mahou Sensei Negima.
