Woof Woof Story, Vol. 3 (light novel)

It's not easy being rich.
For where there is treasure, there will be treasure hunters. So when the mansion
is set upon by thieves, Routa begrudgingly comes out of retirement, yet again,
to defend his home and his leisurely way of life. But to his surprise, Zenobia,
the freeloading knight who purportedly hates his guts, joins the cause! What a
tsundere...