Godai Yusaku
Godai is a troubled student with very little money. He has fallen in love with the apartment manager. Living in room number five, he, as Kyoko would put it, gets into strange situations that no one else could possibly get into. He is often visited by his grandmother, Yukari, who lives with his parents in Niigata city.
Otonashi Kyoko
Kyoko has recently recovered from her husband's death, and is trying to figure out her life, between keeping the memory of Souichiro-san alive and her own feelings for other people. Her dog is named Souichiro-san after her late husband. She is still on the Otonashi family register, but her parents want her to get off and come home or remarry. However, she decides that she would rather work for Grandfather Otonashi, who owns Ikkoku-kan. She also has a niece, Ikuko.
Mitaka Shun
Godai's rival of love. They both are trying for Kyoko's affections. Mitaka is a charming, rich tennis coach. Unfortunately, due to a childhood incident, he has a fear of dogs.
Yagami Ibuki
Godai's former student who has a crush on him. She is the type of person who usually gets what she wants.