Sumika Shiun is a fictional character from Gakuen iDOLM@STER, a school-life idol-themed spin-off in the iDOLM@STER franchise. She is a student aspiring to become an idol, and her story centers on training, growth, and the challenges of balancing school life with entertainment ambitions. As part of the cast, she helps represent the series’ focus on young talent developing their skills, personality, and stage presence while building relationships with other aspiring idols.