Koi Cupid/YMMV

• Nightmare Fuel: The glimpses of demons.
• Tear Jerker: At the end of the first volume, Ai insists on making sure Lizette is safe, even though the nearer they get to the demon world, the more the poisons in the area affect Ai. Lizette is unmoved at first, even planning to use the opportunity to kill her. Ai eventually collapses and begins to fade away, still wishing she and Lizette could be friends...and Lizette tells the other angels where to find Ai.
• What Do You Mean It's Not for Little Girls?: Apparently it's a seinen manga, though not obvious by the first volume.