Left column is from the Classic Rockman (Megaman) series: Rockman, Blues and Forte (or Megaman, Protoman and Bass, if you prefer).
Right column is from the Rockman X (Megaman X) series: Rockman X (Megaman X), Zero and Axl.
Try and see the similarities.
As to why I insist on using their Japanese names, they're what I'm used to (and they sounded more name-y-like to me).
Rockman, Rockman X and related characters belong to Capcom.
Line art: pencils
Coloring: Photoshop 6