担任から、クラスへの貢献度が低いという理由で「性処理当番」に任命されてしまった空ちゃん。1週間で精子をビーカー一杯まで溜めないと、退学にされてしまうと告げられ、ひたむきに精液採取に励む。初めは恥ずかしかった当番だけど、これで男子の成績向上につながるなら一生懸命頑張ります！

Sora-chan has been appointed "sex duty" by her homeroom teacher because she hasn't contributed enough to the class. She's told that if she doesn't fill a beaker with sperm in a week, she'll be expelled, so she diligently works to collect semen. At first, she was embarrassed about the duty, but if it helps improve the boys' grades, she'll do her best!