Toru Takayama worked part time and lived in a single apartment.

On his way home he saw a girl being attacked by a man. He intervened and saved her.
Her name was Airu Nekogawa.

Toru started to say goodbye when she grabbed his sleeve in desperation.
"Please, I have nowhere to go..."

He offered her a place to stay for the night, no strings attached.

Little did he know she was the one with the hooks. As an out-of-work freeloading otaku
Airu was about to set down roots and mooch off of Toru...

[From DLsite English]