Daa! ^3
A comedy-romance anime based on the manga by Kawamura Mika tells the story of two unrelated teens who become guardians to an alien baby and it's baby sitter. Although at first, it may seem childish, much like BuBuChaCha, it's actually not. I'd say it's a little Ranma 1/2 minus the martial arts and weirdness, a little Kare Kano minus the drama and monologues, and a whole new world of its own.
Basically, Miyu's parents had to leave for the US to work for NASA, and thus left her with their family friend, Saionji and his son Kanata. However, fate had it that Saionji also had to leave for India to undergo training, and so now, the teens are left to fend for themselves. To make matters worse, an alien baby, Ruu, and his babysitter, Wanya crash lands on Kanata's home, which is a shrine by the way. Having nowhere else to go, and fearing for their safety, they were hopelessly taken in by the teens.
I'll stop there, so as not to spoil anything for future viewers. If you're looking for something relaxing, funny, with a little romance, you should consider watching this.