Today's Cerberus

Today's Cerberus (今日のケルベロス, "Kyou no Cerberus" ) is a manga by Ato Sakurai. It began its serialization in Square Enix's Shounen Gangan magazine in May 2013. Yen Press has licensed it for English release.

Plot
When Chiaki Mikado was a child, he encountered a strange, three-headed puppy. After that puppy bit him, he lost part of his soul. As a teenager, Chiaki finds himself unable to enjoy anything in life, but the three-headed dog returns in human form(s) to fix that! As it turns out, the dog that bit him was Cerberus, and the three heads are all unique individuals that also happen to be pretty young girls! With his new roommate(s) helping him, can Chiaki finally find happiness?