Funny Tortoise is notorious thief and master of disguise who disguises himself as Uezawa, Kokoro, Kaji and as a policewoman by the name of Itou to steal a valuable locked book (which turns out to be Jordi's diary) from the library. He travels in a hot-air balloon with a tortoise logo on it. He is also talented at imitating other people's voices. Though a criminal, he has a good heart and helps Kokoro on several occasions.

Aigame is the thief's true identity. He met the girls' parents as a 14-year-old soldier with no family. Before the army, he was a thief, working his way up from petty theft to highway robbery. As punishment, he was forced to join the army. He often argues with Kajihara. After the war, he disappears, leaving behind a note simply bidding everyone farewell. Jordi speculates that he has returned to his old life of crime, which, of course, turns out to be true.