Hatsumi is Hazuki039s adopted older sister and love interest albeit Hazuki039s love is onesided. Hatsumi appears to be mute though it is proven otherwise on several occasions and communicates mostly through gestures and facial expressions. Despite being older Hatsumi is much shorter and thinner than Hazuki. Childhood memory flashbacks show Hazuki as a small sickly child who might not have lived if not for Hatsumi039s care. Although it seems that Hazuki039s love is onesided episode seven shows that Hatsumi does have feelings for Hazuki and was trying to express herself as best as she could with the knowledge that she cannot stay beyond her sixteenth birthday suggestions of this were shown along the way by her sending Hazuki anonymous love letters mdash later expressed in full and in words toward the end of the anime. In the first episode Hatsumi disappears in a burst of green light quotsmaquot at midnight on her sixteenth birthday as Hazuki tries to steal a kiss in her sleep. The events that follow lead Hazuki to a mysterious library in another dimension in which all the worlds are kept in books. Hazuki learns from the Library guardian Lilith that Hatsumi is only one of the forms of the previous guardian Eve and that Eve stays in different books for fun until she turns sixteen.