Known as the 2nd Generation "Oujousama" (Princess / Lady) of the group, Yumiko is often teased and called "Chairman Yumiko" by her fellow members. Yumiko is especially known to be a good player in Mario Kart, relentlessly beating Inoue and even Habu who is often regarded as the number one gamer within the group. She also likes anime and manga, sharing the hobby with other members such as Matsuda. In particular, she like Hunter x Hunter, with her favorite character being Chrollo. She bought a camera and carries it around daily to take pictures of members and landscapes to keep the memories fresh. She usually uploads these photos to her blog, tagging it with "#yumikocamera". Yumiko is also known to spoil the 2nd generation members by handing down some of her clothes and giving them food (such as ice cream), and she sees herself as Takemoto Yui's mom.
