Hakase

The Professor is the protagonist of the story, although his name is never revealed and he rarely speaks — his creation (Robo, his only companion) rephrasing his answers to the reader instead. A few years after the mysterious disease wiped out humanity, he and Robo spend their days looking for other people that may have survived.

He was friends with a female classmate, whom he unknowingly inspired to become a robotic engineer. In his diary, the Professor describes a lonely childhood marked by bullying, eventually leading to the nickname "Professor" for his reclusive personality.