Today's attack is heart shaped bubbles. They've actually gotten inside the house somehow. When they pop, rather than just turning into a little drop of liquid, they'll actually emit sounds, or rather words.

"Someone loves you, Dio!"

"You're never alone!"

"You're worth caring about!"

"Don't forget someone cares about you!"

"Smile!"

The voice is, of course, Mikado's. But Mikado himself is nowhere to be seen, unless anyone actually wants to go poke around the street outside trying to find his hiding place.