Maribel Hearn is a prominent character in ZUN's Music Collection, specifically known from the 'Seihou Project' and 'ZUN's Music Collection' albums. She is a university student at Kyoto, with the ability to perceive boundaries, including the boundary between fantasy and reality. This unique skill often leads her to experience supernatural phenomena. Maribel is a member of the 'Secret Sealing Club' alongside Renko Usami, and together they explore the mysteries of the world, blurring the lines between reality and fantasy. Her character is significant as she often acts as a bridge between the real world and the fantastical realm of Gensokyo.