yamada hiroko

One of three individuals residing within Guu's stomach world, she first appears in episode 8 of the TV series. She is a 22-year-old who attempted suicide by jumping into the ocean and was subsequently rescued by Guu, who inadvertently swallowed her while fishing (and while catching a massive haul of various sea life, she technically wasn't part of the catch). Unlike Seiichi and Tomoyo, Hiroko exhibits mental instability and bipolar disorder, making her dangerous and unpredictable. Indeed, she had devised an elaborate plan to take revenge on her unfaithful husband by dying, enduring hell, and returning as an evil spirit to haunt him for the rest of his life. Now, she spends most of her time in Guu's stomach world drinking alone on a hill, a place most other inhabitants have learned to avoid. She became fast friends with Yumi-sensei when Guu had temporarily swallowed Yumi.