Rinka Kunitachi is a prominent character in the anime series 'Kono Naka ni Hitori, Imouto ga Iru!' She is known for her refined elegance and comes from a prestigious family. Her character is initially cold and distant, but she gradually reveals a warmer side as she becomes more involved with the protagonist, Shougo Mikadono. Rinka serves as the student council president and is deeply committed to her duties, often showcasing her intelligence and leadership skills. Throughout the series, she plays a key role in the unfolding mystery surrounding Shougo's search for his long-lost sister.