The annual health checkup day has arrived, but this year's examination takes a strange turn. The doctor's inspection focuses obsessively on the anus, using fingers to loosen the anal ring. The schoolgirls are made to crawl on all fours as anal beads are inserted, then placed on delivery beds where anal vibrators are used to torment them. For some reason, the girls in uniform cannot resist these positions, gradually becoming captivated by the sensations. "Sensei... my body feels weird..." the schoolgirls cry out, trembling through their first experiences of anal training. The video captures their gradual descent into this new, overwhelming world.