"DearS" is a science-fiction romantic comedy manga series set in a near-future Japan where an alien spacecraft crashes into Tokyo Bay. The aliens, known as DearS, are a humanoid species who integrate into human society, offering their advanced technology in exchange for shelter. The DearS are designed to serve humans, and their submissive nature leads to their rapid acceptance by society. However, their integration is not without controversy, as some humans view them with suspicion.

The protagonist, Takeya Ikuhara, is a high school student who lives a relatively ordinary life until he encounters a DearS named Ren. Ren, unlike other DearS, becomes separated from her group and is found by Takeya in a weakened state. Despite his initial reluctance, Takeya takes her in, and Ren quickly becomes attached to him, referring to him as her "master." Ren's behavior is overly affectionate and dependent, often causing comedic misunderstandings and awkward situations. Her lack of understanding of human customs and her unwavering loyalty to Takeya create a dynamic that drives much of the series' humor and conflict.

As the story progresses, it becomes clear that Ren is not an ordinary DearS. Her unique traits and abilities set her apart from others of her kind, hinting at a deeper mystery surrounding her origins. The series explores the growing bond between Takeya and Ren, as well as the challenges they face from both human and alien forces. Takeya's friends, including his childhood friend Neneko Izumi, add to the interpersonal dynamics, with Neneko harboring feelings for Takeya that complicate her interactions with Ren.

The narrative delves into themes of coexistence, identity, and the complexities of relationships, both romantic and platonic. The DearS' integration into human society raises questions about trust, prejudice, and the ethical implications of their servitude. The series balances lighthearted moments with more serious undertones, particularly as the true nature of the DearS and their mission on Earth is gradually revealed.

Supporting characters, such as the stern DearS leader Mitsuka and the enigmatic scientist Dr. Shūji, contribute to the unfolding plot, adding layers of intrigue and conflict. The story builds toward a climax that explores the consequences of the DearS' presence on Earth and the choices they must make regarding their future. Through its blend of humor, romance, and science fiction, "DearS" presents a narrative that examines the intersection of humanity and alien life, wrapped in a comedic and often heartfelt package.