Namco X Capcom is a manga based on the video game of the same name. It is not an adaptation of the game, but rather an anthology consisting of various stories that use characters and elements from the game. At least two of the stories center on Klonoa and Guntz. Just like the game, they are allies to Reiji and Xiaomu. Other characters that appear are Janga, Joka, The High Priestess, and Grandpa.
One of the stories depicts Klonoa as a monster. This is the only time in any form of media that he is portrayed as a villain.
Grandpa is the only Klonoa character to appear in the manga that did not appear in the game.