It said that despite the ComiPo devs hold all copyrights on the premade assets in the software, they said that they will not hold copyrights on user-made content such as composition of characters, panels, story, etc.. And that it could be no problem when using character images in another software.

However, that is just the basic things. For more specific usage, I need to wait until the devs reply to my inquiries. However, it might be super slow for them to reply to my inquiries (I checked my inbox several times throughout the recent days , but there is still no reply; only e-mails containing replies from Reddit and Game Jolt users in my posts appear after my inquiry).

I hope you might find this fact useful if you plan to create a character in ComiPo, export it as an image, mod it using external graphics softwares (such as Krita, but you also need to keep it super realistic in order to not make it resembling a create.swf image placed over a ComiPo model image, but to make it resemble the ComiPo visual style (again, you SHOULD NOT copyright the art style that use for the image mod)), and then use it inside your doujinshi works!