Mayumi Imoto

Mitsu Higashi High School, Class 2-C. She joins the rowing club to defeat her rival, Taeko. Though she and Taeko frequently argue, they actually know each other well. She often helps out at her family's long-established fishery. She speaks in a refined, ladylike manner but is nicknamed 'Imocchi' by Taeko.

(Source: Official site, translated)