Narusegawa, Mei

成瀬川メイ

Mei-chan is Naru's younger sister. Naru refers to her as her "half-sister" in manga volumes 11 and 14. Conversely, in the anime's episode 22, Mei states, "My father married her mother." This prompts some to speculate that they are step-sisters, though this remains unconfirmed. Initially, she attempts to bring Keitaro and Mutsumi together, hoping Naru would return home if Keitaro were taken. She abandons this plan after she and Naru resolve several family misunderstandings. Additionally, in Love Hina Again, she makes a brief appearance to assist the Hinata residents regarding Keitaro and Naru's relationship and to help accelerate it. She also appears in the manga's final volume, standing aside with the rest of the Hinata Inn residents while Naru chases Keitaro after he accidentally strips her. She plays a minor role in the Spring Movie as well.
The character of Mei-chan was created for and primarily appears in the Love Hina anime, although she is mentioned in at least two places in the manga and appears in the final chapter of the manga's last volume.