Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
DearS (ディアーズ, Diāzu) is an ecchishōnen Japanese manga series co-written and illustrated by Banri Sendo and Shibuko Ebara, credited under their pen name Peach-Pit. It was serialized monthly by MediaWorks in their magazines Dengeki Comic Gao! from October 2001 to September 2005 and Dengeki Maoh from October to November 2005 and was later published into ten volumes by the company. The manga was licensed and translated into English by Tokyopop. A 13-episode anime was adapted by MSJ and a PlayStation 2 video game was produced by MediaWorks.
Plot
Exactly one year prior to the beginning of DearS, humanity made unprecedented contact with extraterrestrial life. Forced to crash land into Tokyo Bay when, en route to their home planet of Thanatos, their spacecraft breaks down, 150 humanoid aliens are naturalized into Japanese society and affectionately nicknamed "DearS"; a portmanteau of the words "Dear" and "Friends". The crashed aliens consist entirely of individuals from a genetically modified "slave race" designed to enjoy slavery.
Takeya Ikuhara is a temperamental seventeen-year-old Japanese student attending the fictitious Koharu High School with a strong prejudice against the DearS. Due to a childhood scare, he believes that the aliens are fake, worthless beings that have generated nationwide overhype and are secretly plotting to take control of Earth.
On his way home from school he discovers a homeless DearS who, after fainting and much to his annoyance, he feeds and shelters in his apartment. The girl, who he nicknames Ren, is infantile and friendly, and grows obsequious and dependent upon Takeya, and calling him "Master", a responsibility he tries to disassociate himself from. Her oblivious tenacity keeps her around, however, and over time, realizing Ren's genuine care and empathy for him, Takeya has a change of heart. Unfortunately, because Ren is deemed defective, DearS headquarters orders her arrest.
DearS began as a manga series co-written and illustrated by Banri Sendo and Shibuko Ebara, credited under their pen name Peach-Pit, which was serialized in MediaWorks' Dengeki Comic Gao! manga magazine from October 2001 to November 2005. The manga was compiled into ten tankōbon volumes released by MediaWorks in Japan. The series was later translated into English and German by Tokyopop, French by Semic Comics and Italian by Flashbook Editore.
DearS was adapted into a twelve episode television and single original video animationanime by MSJ with co-production by Bandai Visual, Geneon Entertainment, Lantis and TeaM DearS. The series was directed by Iku Suzuki. The series was broadcast on Chiba TV, TV Kanagawa, TV Saitama, Tokyo MX TV, TV Santerebi, TV Aichi and TVQ Kyushu from July 10 to September 26, 2004. Four DVD compilation volumes were released from August 2, 2005 to February 21, 2006. The anime's opening theme is "Love Slave" (ラブスレイブ) by Under17 and the ending theme is "Happy Cosmos" by Poppins. The anime has been re-licensed by Discotek Media.