Shuri Wakatsuki and her twin brother Syūsuke were close friends of Sana Hidaka before he moved away 5 years prior to when he moved away.
SpoilerShuri, along with Shuusuke, are abused by their father who is obsessed with being promoted and live with him along with a women that lives with them because of their fathers money and sex. Their real mother died prior to the beginning of the series and to hide the fact of their torn apart family, the twins act silly and lightening when in the presence of others.
MAL
