Hazuki Kudou, Kiyoka's older sister, who is asked to become Miyo's teacher to prepare her for the high life. She ended up really liking Miyo and treats her like an actual sister. She actually likes Miyo more than she likes Kiyoka lol. Miyo eventually starts calling her neesan in vol 3. Honestly its volume 2 where the story really gets going. We got introduced to Miyo's family from her mother's side and the reveal of miyo's power.
In volume 3, miyo and kiyoka goes to the Kudo family home where Miyo meets her soon to be in-laws. While kiyoka's dad is very accepting of Miyo, his mother definitely wasn't. But eventually, she does accept her after seeing how dedicated Miyo is to Kiyoka. Miyo and Kiyoka also has their first kiss here
In vol 4, Miyo meets an old fiancee of Kiyoka. While at first she feels a bit awkward, Miyo ended up becoming good friends with her. During the ending of this volume, Miyo and Kiyoka has their second kiss while its snowing outside. The description is just beautiful