Yumi Dreamweaver is a small, sleepy girl with pink hair and narrowed eyes. She speaks like a robot or shows emotions due to her perpetual sleepiness. However, under a blanket, her mischievous side emerges, and she becomes an expert tickler, delighting in making others laugh uncontrollably until they pass out. Her talent for tickling led her to join the Tickle Foundation, where she uses her skills responsibly and finds a sense of belonging. She adressess people as "Big brother" or "Big sister".