Amasawa-kun to Kamuna-chan

One day while taking a walk, Amasawa-kun meets the Kamui Artificial Human Number 7 (Kamuna-chan), who happened to fall on the side of the road. Amasawa-kun, who has a habit of collecting weird things, picked up and brought the lost "thing" home. Just like that, they are now living together, but their lovey-dovey life is so sweet that you'll feel embarassed watching it.

(Source: REX Comics, translated)