Assassination Classroom Vol. 5 (manga)

Intramural relations are at an all-time low: Principal Asano wants to crush Koro Sensei's 3-E baseball team while Koro Sensei wants to avenge Principal Asano's sabotage of 3-E's midterms. Then the government sends in a new Special Forces operative—a ruthless father figure who tests Karasuma's combat coaching skills. You'll never guess which student does him proud! And when Koro Sensei digs a swimming pool to help his students cool off, they discover a new weakness of his—as well as how cute their classmates look in swimsuits!