No idea, but I hear that the Manga is extremely weird. Someone said it's full of "Toilet humour" such as Clank crapping missles at times o_O (in the first issue) and everyone is out of character compared with the games. Basically, the Manga is the Japanese version of the entire series. Even the story does not follow the games at all! This is the plot for the first issue…
Ratchet is a total loser who flies around in space and thinks he is a hero. Nobody really cares for him, and ignores him whenever they can. But when he finds a strange, talking robot named Clank (which he accidentally hit with his ship) and offered to repair him, Clank joins Ratchet on his team. But the peace doesn't last for long. When the Mayor calls almost all the time, and Captain Quark comes outside of the TV whenever Ratchet or Clank uses it, everything turns into trouble.
Join Rachet and Clank on their misadventures to save the galaxy once more! Even if it'll break you down in laughter…
Sounds really weird, doesnt it XD? Once I get the Manga issue 2, I hope I can find someone who can translate it… :p I found an auction for the issue 1, so I'm trying my luck with that.