Yufuin's inspiration leads the Defense Club decides to go on a training camp to the ocean on . Meanwhile, the three student council members head to a beach resort in a limousine. The beach has bright sun and white sand, but there's something a little off about it. A strange feeling starts hovering around the group's members...
More importantly, I want to know 
who used my toothbrush!
Aber zuerst will ich wissen,
wer meine Zahnbürste benutzt hat!
¡Antes que nada, tengo que saber 
quién usó mi cepillo de dientes!
¡Antes que nada, tengo que saber 
quién usó mi cepillo de dientes!
Mais finalement,
Piuttosto, voglio sapere 
chi ha usato il mio spazzolino da denti!
Mas eu ainda quero saber quem usou
 minha escova de dentes!