Katagiri is a loan collection officer at a Tokyo bank. One day after work, he finds a giant frog over six feet tall waiting for him in his apartment. Frog apologizes for barging into his home and has made tea in anticipation of Katagiri’s shock. Katagiri thinks that someone is playing a joke on him, but he gradually accepts the reality of Frog. He cautiously asks if Frog is affiliated with any gangs and tells him that he has no authority to negotiate his loan payments. Frog laughs and explains that his purpose is to save Tokyo from destruction and that he needs Katagiri’s help.

Frog agrees to answer Katagiri’s questions to ensure that they understand each other. Frog vows that he is neither a literary device nor a deconstruction and loudly croaks, “Ri-i-i-bit!” (84), to prove that he is a real frog. He tells Katagiri that a devastating earthquake will strike Tokyo and cause more destruction than the Kobe disaster. The epicenter will be directly below Katagiri’s bank. Frog plans to go underground and battle Worm, a dormant creature who has been absorbing the world’s vibrating hatred for decades. Frog does not consider Worm evil and accepts that such a being is entitled to exist.