Seventeen Years Old Don't You Want To Grab Your Wrinkles? / Duty and Soldiers / Don't Say It So Casually! Melos Stood and Retorted Furiously

Harumi Fujiyoshi is listening to a Zetsubō Sensei radio show at home while working on her yaoi dōjinshi. The radio show is actually derived from a chapter of the Zetsubō Sensei manga, which portrays Japanese people's indifference to their ages and introduces a new character, Manami Ōkusa, who is a married high school student. In the second part of the episode, Nozomu criticizes the society where individuals are compelled to serve their 'duties' to meet other people's expectations. These 'duties' are often very superfluous and trivial. However, Kafuka points out the irony that Nozomu himself is a part of such a society, as the girls around him are expected to serve their various 'duties' to take care of their teacher. In the third part of the episode, Nozomu is in despair about society, where serious matters are often taken too lightly. Several of Nozumu's students provide their experiences of such a trend. After Rin Itoshiki makes an appearance as one of Nozomu's new students, Nozomu and his students decide to reverse the trend by treating various trivial matters with serious attitudes, which eventually becomes an addicting habit for everyone.