Love Hina Again (2002)

Keitaro, Naru, and all their friends are back in an animated series based after both the specials. Keitaro's still trying to get Naru, but he isn't the only one. Of course, the other person's trying to get Naru in a different way. Keitaro's sister, Kanako, has moved into the house as the temporary manager. From the start, she has a grudge against Naru, because of her "relationship" with Keitaro. Kanako tries everything she can to make sure Keitaro and Naru can never be together, ever.