Yuka Koizumi challenges the popular series "Geki Piston" that counts the number of times you poke during FUCK! Although he starts counting himself, he forgets the number of times in the piston pleasure and keeps panting! Squirting with vibe blame & finger fuck! Ride on the back, shake your hips in the standing back and roll up! The total number of pistons has finally exceeded 20,000, and this work is a special volume!