150 extraterrestrial beings arrived on the shores of Kasai via a UFO last year. Regrettably, their spaceship was beyond repair, which led Japanese authorities to grant them citizenship under the moniker "DearS." To adjust to human society, the aliens learned Japanese customs, language, and culture. A homestay program was introduced by the government to facilitate their integration. One inclement morning, an alien capsule was accidentally dropped on a riverbank by a truck. The being inside was set free, and a high school student by the name of Takeya Ikuhara discovered her. Despite his initial distrust of extraterrestrial life, he decided to assist her. The alien was named Ren and imprinted on Takeya, becoming his personal "slave." This changed Takeya's life drastically, as he was now in the constant company of a compatriot, despite his earlier intention to abstain from any association with aliens.