Everyone calls her Osaka...
Ayumu Kasuga is a transfer student from Osaka, Japan. Tomo Takino expects her to act like the stereotypical Osakan — loud, like a hillbilly, chose for her the nickname "Osaka", although her behavior could not be more different. She reminisces how people in Osaka consider her "slow" and "spacey", at least compared to the average Osakan, but she lacks the energy or motivation to change. Osaka was the first to ever lose a race against Chiyo Mihama. The nickname sticks so well she is called 'Osaka'

Aged up to 18 btw