Night of the Beasts Series by Chika Shiomi

Aria's got a reputation as the toughest girl in school because she can't resist taking on bullies. She's taken by surprise when her first kiss is stolen by a complete stranger. Not only does he keep making moves on her, but it seems like every time they meet, it's at the latest crime scene of a murder spree that's plaguing Aria's neighborhood.

Aria's life will never be the same now that she's met Sakura, the kind young man whose body houses a vengeful demon. Our heroine falls deeper into the web of darkness when she learns the details behind how this curse befell poor Sakura and who is now out to kill him. It only gets worse when Aria realizes her enemies are closer than she'd thought.

The raging beast with Sakura takes form and a new villain joins the scene! Our tale moves to the remote location of Sakura's lineage's temple where Aria is ready to stand her ground against the now materialized demon. But this new transformation has made a swap with Sakura's form. Will Aria have the strength to protect those who depend on her?

The demon posessing Sakura grows stronger, and Aria refuses to back down! Despite her newfound determination to save him, things are complicated by a stranger who seems to posess the same powers! As Aria fights on, Sakura manages to regain enough control to speak to her...and Aria lowers her guard long enough for the demon to break through.

Old friends and old grudges are revealed in this volume of 'Night of the Beasts', as Aria and Kuguri go up against the demons Kagara. Though she's determined to get Sakura back, she realises that fighting might not be the only answer. But will this new tactic work, or simply leave her vulnerable to the ruthless demon within Sakura?

Sakura is finally free of Kagara, but at a terrible price! As Aria holds her dying love, she makes one last attempt to free the demon from his own rage and hatred as Kuguri makes the ultimate sacrifice for her master.