Black pants in cartoon leg art usually depend on the artist's choice. They can be made to look bold and striking with a single color, or have added elements like patterns or highlights to make them stand out. Different cartoons have different approaches to showing black pants on legs.
Spacetoon's old cartoons stood out for their emphasis on friendship and adventure. They were visually appealing with bright colors and had plots that could keep children hooked for hours.
You can start by sketching out the basic outline of the characters or objects related to the birthday. Then add colors and details to make it look lively.
Honestly, it's hard to say. Maybe it's related to a creative idea for a story or an art project. But without more details, it's hard to figure out exactly what it represents.
The raw version of Devil Survivor manga can sometimes be found on certain Japanese manga platforms or through private collectors. However, accessing it through unauthorized means is illegal and not recommended. You could also check with manga libraries or local comic book stores to see if they have it available.