Natsuki Ikuhara  

The story revolves around Takeyas younger sibling who has recently returned from abroad. At first, she forms a close bond with Ren, but her feelings towards her shift when she hears Ren describe herself as Takeyas "slave". This leads to the sister becoming hostile and attacking her brother for being a "pervert." The portrayal of this character deviates from the typical cute little sister archetype commonly seen in anime.