One day, the elderly-looking transfer student Tanaka Shori, AKA Billy, arrives at the school. He proclaims himself a scientific genius, but he's actually a commander in the enemy organization! He declares that he'll use his own formula to ascertain Twin Angel's secret identities, but...
Yuimaru! 
The Field Trip to Okinawa
يويمارو! الرّحلة الميدانيّة لأوكيناوا
Yuimaaru! Schulausflug nach Okinawa!
Yuimaru! Gita Scolastica a Okinawa
Yuimaru! A excursão para Okinawa!
Юймару! 
Поездка на Окинаву