Female. A mermaid princess who once longed for the surface and fell in love with a human prince, but turned into foam when it didn't work out. Reborn as a human in Lake Biwa, Shiga Prefecture after about 200 years, she seeks true love once again. Because she once lost her voice and was reincarnated, she has a scar on her tongue. Her curiosity has been immense since the moment she was born. She is currently obsessed with dramas to learn about the common sense of the outside world. She cries uncontrollably whenever she watches melodramas, which troubles Mari, her roommate. Being a mermaid, she has a unique talent: picking out good fish. During a grocery trip with Mari, she showed off a feat of identifying fresh oysters just by looking at their shells. Possessing the exceptional beauty of a princess, she drew everyone's gaze when she secretly entered the school wearing Mari's uniform.

Female. A high school boxer living in Otsu City, Shiga Prefecture. She lost her mother at a young age and lives with her grandmother, father, and older brother. She meets the displaced Lara and ends up living with her. Though she is cool-headed and rarely shows emotion, she is very kind deep down. Having kept a talking fish named Witch Gon-chan since she was a child, she seems accustomed to the supernatural. Her skills as a boxer are outstanding; she won a national tournament in middle school and currently trains with second and third-year students despite being a freshman. Contrary to the athlete stereotype, she is quite diligent with her studies. Though she appears blunt, she constantly looks after Lara, who is prone to getting into trouble. Lara carries around a cocoa can given to her by Mari as a flowerpot and also treasures a catfish plushie that Mari liked as a child. She speaks with a natural Kansai accent rather than a heavy dialect (using it closer to standard speech but with the distinct intonation).

Male. A boy Lara met in Shiga. His appearance closely resembles the prince Lara fell in love with 200 years ago.

Male. Mari's older brother. Skilled at riding motorcycles. A high school senior. He frequently skips school but is very popular. He doesn't even bother taking exams much because he has no intention of leaving Shiga Prefecture. Unlike his cool and stiff younger sister, he has a sly and playful personality, though they share the same underlying kindness. He speaks in a Kansai dialect.