OK, my concept and challenge is to write a story about a "tickle duel" - a science fiction story set on a planet or in an alien culture where dueling is common, and duels are settled by tickling.
My original though is to have the duelists each tickle the "seconds"/lees of their opponent, but other variations are possible: Both duelists get tickled by the seconds of the other, both get tickled by a machine, or by a neutral third party, or both duelists tickle each other, or the challenged gets to tickle the challenger.
HOWEVER: and this is where the story-writing challenge comes in - winning the duel is NOT based on how quickly the ler can overcome the lee's endurance, or how long the lee can hold out against the ler's attentions, but by some other measure. The amount of "tickle energy" each duelist can produce when he or she is tickled, perhaps. Or which duelist is the most skillful tickler, as judged by a neutral lee-judge (or panel of two or three judges).
Or... your challenge, if you choose to accept it, is to figure out something other than "see how quickly the lee's resistance & endurance can be overcome."