Hatsune Kawamura

Hatsune Kawamura is the older sister of Futaba Kawamura, who is the love interest of Yuuki Kamiyama. She first appears in Volume 6, Chapter 3 "A New Life".

She becomes very friendly with Yuuki and offers to cook dinner for him after seeing that he was alone and eating unhealthy, much to the irritation of Futaba. She is dating Shuuto, a former band member and currently teaching at Yuuki and Futaba's school.

In the conclusion of the story, she moves to their hometown along with her fiancé.

Personality
She is an easy-going, cheerful and honest girl who is totally in love and devoted to her boyfriend. However, according to Futaba, she has the habit of attracting all sorts of creeps due to her amiable personality.

Futaba Kawamura
Futaba is the younger sister of Hatsune. She and Hatsune were living together before Co-Op Yamashina burned down. The sisters have a very loving relationship where one looks out for the other. Futaba's love for her sister was so strong that she refused to make a move on her crush for the sake of her sister saying that nothing compares to seeing her sister happy.

Shuuto Kimura
Shuuto Kimura is Hatsune's boyfriend and later fiancé in the story. They have been dating since college and are equally faithful and loving to one-another.

Yuuki Kamiyama
Yuuki met Hatsune at first when he was going to his apartment. Formerly, he did not know that she was the sister of the girl he had accidently groped the morning of the same day. Hatsune being the friendly person she was invited him to take a bath then later offered dinner as an apology. She is very supportive of her sister's relationship with Yuuki and in the final chapter, it was she who encouraged Futaba to go after him adding that family will always be family but it takes effort to be with the someone one loves the most.