Kaoruko Sazaki is the younger sister of Susumu Sazaki from the previous season. She is the leader of Saint Odessa Girls' School's Gunpla Battle team "Song Dynasty Vase", which made the top four in the previous year's West Tokyo regional qualifiers. Kaoruko is nicknamed "Gyanko" for her use of the YMS-15 Gyan in Gunpla Battles.
(Source: Wikipedia)