Rina Takamiya is a classmate of Meimi and Asuka's, and she meets the later in an arcade where she tries to beat a video game for him, much to his dismay. There she witness the delivery of a calling card from Saint Tail, and appears at the location the card indicates, claiming that she will catch Saint Tail because she wants to become a police woman. Along with Asuka she fails, although she is then determined to capture the theif.

As the mayor's daughter, Rina is able to accompany Asuka on his mission to capture Saint Tail. And she soon develops a theory who Saint Tail is, at the same time developing feelings for Asuka herself. She tried reveal Meimi as Saint Tail numerous times, but failed. She also offered to tell Asuka who Saint Tail really was, but he declined, claiming he would catch her on his own to find out.

Rina is a headstrong and stubborn character, she is also physically strong, which balances with Meimi's agility. At the beginning of the series she is also a little taller than Asuka, however, he grows over the series, which sparks some of her feelings for him.