I managed to track down that the character and the quote are from Medaka Box, and even find pictures of the full page they're from, but for whatever reason not which chapter, so if anyone more familiar with the manga can point me over there, the reference can probably be made a bit more accurate.

All things are settled via a Children's Card Game.

ithekro said:

All things are settled via a Children's Card Game.

*boundary-soccer-gensokyan-roullete-nth-dimensional-yukkusphere-shogi-srip-poker