A young man named Yuichiro Kinosaki, after studying abroad for half a year, gets a shocking homecoming when he discovers that his inventor and scientist father has given his three dogs the body and appearance of human beings. Now that his dogs have become three beautiful girls, he will have to cope with the amusing changes of feeding them, walking them, bathing them and more in his everyday school life.
Yuichiro Kinosaki is the main character of the story. After returning home from studying abroad, he is shocked to find that his three beloved dogs, Elga, Luna, and Rino, have turned into human beings. Everyday tasks such as walking and feeding them cause him endless trouble. He has a dream of becoming an astronomer or an astronaut.
Elga is a Alaskan Malamute, Yuichiro's first and most beloved dog (at first it was because she was with him since his mother's death). Elga is gentle, obedient and she has been by Yuishiro's side since his mother died when he was very young. Before Elga became a human, she always dreamt of speaking and doing the kinds of things that Yuichiro did. She is always trying her best to make Yuichiro happy. Elga has a lot of fears, ranging from mice to water, but she is more than willing to face them if it makes Yuichiro happy. Elga has some feelings for Yuichiro as shown in the last two chapters of the manga, where she decides to return to her dog form so she does not have to be apart from Yuichiro when he leaves the country, and when she returns to her human form during the last chapter, in which she kisses Yuichiro.
Luna is Yuichiro's second dog. She is a Cardigan Welsh Corgi. Of the three dogs, she was the first to kiss Yuichiro (copying what she saw on television). She is the youngest and the one who always is the most energetic. She enjoys playing around with the garden hose and the vacuum cleaner. Apparently, she also likes Wan-Wan biscuits. She does not like clothes very much, and is always ready to play.
Rino is Yuichiro's third and last dog. She is a Doberman Pinscher. Though she is generally quiet, does not play much, seldom smiles and has a very short temper, she is mature and very strong. She is always alert, and is like a mother figure to Elga and Luna. It is revealed later on that she was once abandoned by her old master, and adopted afterward by Yuichiro's father. It is hinted that she may have feelings for her master (Yuichiro's father), as seen in chapter 13.
Emina Kusunoki is a classmate and childhood friend of Yuichiro's. She is a very nosy and energetic girl. A little self-conscious about her body, she is always taking note as to how big the girls' bodies are, mostly Elga's. Though she is stunned at first about the dogs, she soon understands and starts to take care of them like a sister. She shows them things such as how to take a bath by themselves and she even shows Elga how to shop at an underwear store. It is heavily implied that she also likes Yuichiro.