Ichimura Kei (english order Kei Ichimura) while initially seen in the ending theme of the anime, is not introduced until episode 6, where she may potentially become Souta's step-sister.
She gets mad at him for telling classmates about the interview, and he misinterprets her insult at him as criticism of his mother Miyoko.
She had a history of being a tomboy and bullying Ichiro in the past.
She lives alone with her dad, Mr. Ichimura. Her mother was a nurse and is rumoured to have eloped with a patient when she abandoned them.
Kei's friend does a lot of activities with her, such as cheerleading.