Episode :
Masaki and Erina, who had been friends since childhood, made plans to visit the beach during their spring break, and Tetsu and Shinobu chose to accompany them. Upon their arrival at the stunning private beach, both couples found joy in playing in the ocean and along the shore. Soon after, while resting on the beach, Tetsu and Shinobu discreetly engaged in sexual activity. However, when they looked to the side, they discovered that Masaki and Erina had observed the entire event. Disregarding all feelings of shame and restraint, the two couples then began to reveal their perverse desires to one another, signaling the beginning of a sexual contest.
