Created by Sanrio and designed by Tomoe Iwata, Keroppi debuted in 1988 with an official birthday of July 10. His full name, Kerokerokeroppi Hasunoue, layers the Japanese onomatopoeia "kero" for a frog's croak with "Hasunoue" meaning "on lotus," reflecting his pond-dwelling life. He resides at Donut Pond, the largest and bluest pond in his world, alongside his family. The Hasunoue family includes father Kerota, a doctor; mother Keroma, a chef and restaurant owner; triplet siblings Koroppi (brother) and Pikki (sister); baby brother Kokero; and grandparents Kerojee and Kerobah, the latter known for storytelling and homemade treats. Keroppi is a small green frog distinguished by large eyes, pink cheek spots, and a signature red-and-white striped outfit. His mouth typically forms a V-shape but alters with his emotions. His personality radiates cheerfulness, energy, and adventurousness. He enthusiastically pursues outdoor activities like baseball, boomerangs, swimming (despite being notably poor at frog-style swimming), and singing. He demonstrates resilience, bouncing back quickly from setbacks or failures, though occasional clumsiness or forgetfulness occurs. His social circle is wide. Den Den, a snail, serves as his constant companion. Keroleen, a fashion-conscious frog who bakes pancakes, is frequently implied to be his girlfriend. Other friends include Ganta, a strong yet timid frog afraid of darkness and heights; Kyorosuke, a tall frog possessing exceptional vision; Noberun, an intellectual frog aspiring to be a weather doctor; crafty cousin Keroppe, skilled at making flower boats and masks; and Teru Teru, a weather-predicting sunshine doll. Beyond his core universe, Keroppi appears across diverse media. He features in Hello Kitty-related animations, sometimes depicted running the Mini-Mart grocery store in Sanrio Town. His video game roles include rescuing Keroleen in the puzzle-platformer "Keroppi's Big Adventure" (1991), plus collaborations like "Pokopang" (2018) and "Hello Kitty Island Adventure" (2023). He also made a brief cameo in the film "Ready Player One" (2018) alongside other Sanrio characters. Keroppi's popularity peaked early, securing first place in Sanrio's Character Rankings in 1990. After a decline in the late 1990s, expanded licensing revitalized his presence, leading to a resurgence marked by a 7th place ranking in 2024. His cultural impact encompasses themed cafes, pop-up hot spring events, and collaborations with brands such as Emotionally Unavailable and Cotton On. He serves as the official mascot for Osaka Shoko Shinkin Bank and represents Japan's kawaii culture globally.