One day, Banzo was sulking on a bridge over Sumida River after suffering a broken heart. As Mikachu attempted to cheer him up, a UFO crashed into the river. Realizing the creatures inside would drown, the two humans salvaged the ship, only to find the creatures inside could not survive in Earth's atmosphere. He build a small, egg-shaped device that allowed the creatures to live comfortably on Earth. He named the device the "Tamagotchi HOUSE" (たまごっちＨＯＵＳＥ) due to its function as both a clock and a home for the creature, and resembled an egg.