Narumi still hates being tickled

Poor Narumi, it's been a while since her friend Ayasa introduced her to the Tickle Club and talked her into a session, she still remembers the absolute agony of being tied up, completely immobilized while her sensitive areas were completely exposed for anyone to tickle as they please. Yet, here she is again, though under different circumstances, it seems she instinctively tickled her opponent's armpit during a volleyball match when they had to jump to reach the ball. Needless to say, it was a foul and she was sent to Ako and Marin to be properly punished for this, now bound to a different device that keeps only one of her arms stretched up.

"Hi, Narumi-chan, we meet again!" Marin says, excited. "Oh no, not you..." she gulps, then Ako approaches her "What do we have here... I heard you like tickling your opponents to get an edge on the matches", her words are met with Narumi looking down and responding "That was an accident, alright? I didn't mean to- AH!". Before Narumi could even finish her excuse, Ako starts to tickle around her bellybutton, she tries to resist, barely stifling her laugh. "Oh, Ako, she tickled her opponent's armpit, actually, like this." Marin says as she then goes for Narumi's exposed armpit, the girl immediately lets out a huge laugh and tried desperately to move around the device. "W-wait! Please stop!" she tries to beg in the midst of her laugh, but the girls are already tickling her mercilessly, her armpits and ribs being the main focus of the assault. "Oh, don't think your other armpit is safe just because your arm is down, I can get through that just fine!" Ako says as she tickles Narumi's covered armpit, sliding her finger between the girl's lowered arm, making Narumi laugh even harder. "Ahahahaha nooooo! I'm gonna die, I can't take this! Please!" she pleads, but the two ticklers are way too amused to stop now, however.