I can't remember this anime I watched. All I know is there were 2 girls sitting at cafe and a bunch of guys came out of the sky, they were after a gem that fell into one of the girls' drinks. The gem was really important so they had to protect the girl that had the gem inside her because she had drank it. By the way I was watching the dubbed version.
I forgot why the guys were after the gem but there were also bad people trying to take the gem. I remember in the 1st episode the girl who swallowed the gem got kidnapped because the gem was inside her.