Kobato
Kobato died long ago, but always had a wish she couldn't rembember. With the angels she made the deal, if she manages to fill up a bottle with the happiness of people, her dream can come true, but if not, she'll never be reborn again and will become wiped out of existence. Arriving in the human world she befriends kindergartner Sayaka, but her brother Fujimoto seems unnaproachable. Kobato wants to be friends with him too, but will she be able to break the walls between them and manage to fufill her wish at the same time?
Chobits
Hideki lived his whole life on the countryside, he actually wanted to study at a university in Tokyo but failed the entry exam and moved there anyways to visit an orientation program. Arriving in Japan's capital, he notices how almost every person walked around with some kind of robots called "persocoms". When his best friend tells him that they work just like a computer Hideki decides to get himself one, since he always wanted a PC but they were too expensive for him and almost having given up, Hideki walked home in disappointment, only to find a mysterious beautiful girl lying on the trash. He immediately came to know, she was a persocom and wondered, why someone would throw such an expensive computer away. She seemed just fine, Hideki thought, so he took her home but noticed soon after that she wasn't like the other persocoms...
Tsubasa: Reservoir Chronicle