The flag of Issui
Not much can be said about this flag, its background color is Issui pink, as usual, and in the middle is a circle, or the sun, representing change and such. The circle is white, possibly because the color white is almost galactically associated with everything that is pure and good. Of course, 'evil' people are considered evil by 'good' people and vice versa, and both consider themselves to be 'good', and as such, both sides sometimes use the color white.
The flag of Issui under the Kingdom of Raisch
When Issui became part of the Kingdom of Raisch, the Kingdom of Raisch merely added two vertical stripes in their, the Kingdom of Raisch's, color. But the ruler of Issui (people aren't sure whether he had proclaimed himself to be a king or whether he was elected after he successfully revolted against the Seleucid Empire), and the nation of Issui with him, was happy to be under the Kingdom of Raisch, now they weren't defenceless, et cetera. It is believed that he asked the king of the Kingdom of Raisch to add two other white circles to the flag, for the Kingdom of Raisch now consisted of four nations (sort of). The middle circle from then on represented either the Kingdom of Raisch, or Issui (so most human inhabitants of Issui say). The second largest circle represented either the Kingdom of Raisch (so the people of Issui said) or Issui, and the other two represented the other two nations under the Kingdom of Raisch.
The flag of Issui when celebrating the defeat of Chipco
A year (on their calendar, not ours) after the Despotism of Chipco had attacked Issui, Issui revealed a new flag, to be used (but not in official matters) a single day in every year. This day was the day when the Despotism of Chipco was defeated and driven from Issui. Currently, it is unknown what day that was, and thus people can vote for which day to use. The only addition to this flag is a new circle to the right of the central circle. This new circle represents Chipco (in reality, Chipco lies to the right of Issui), with many holes in it to represent their defeat. Now, the people of Chipco generally laugh at this, but in the beginning, people grumbled and tensions raised. But no violence or anything happened, fortunately.