Isumi Saginomiya  

, 鷺ノ宮 伊澄

Isumi is a black-haired girl who frequently wears kimonos. Nagis close friend, she met Nagi at a party many years ago. When other children, including Sakuya, ridiculed Nagis initial attempts at writing her own manga, Isumi showed interest and asked about the ending. In response, Nagi jokingly proposed marriage to Isumi. Like Nagi, Isumi is wealthy but unlike her friend, she is gentle, kind-hearted, and skilled in cooking. Although she has a poor sense of direction, she frequently gets lost due to forgetting where she's going. Despite this, she can vanish from people's sight instantly. She harbors feelings for Hayate and wishes to prevent him from being sad.