Hotels in Oarai and Isosaki Oarai Shrine

I was wondering about hotel booking in Oarai town, closr to Mito, Ibaraki prefecture.

I was interested in Oarai Isosaki shrine to take photos during sunrise.
To get there before sunset you should either drive by car or live in one of local hotels (first train is about 6-30 am ...that is kinda late, even from Mito).

I find lots of hotels in Oarai at booking, agoda, holelscom etc. But none of them is available any date in summer, autumn in 2019. I tried different dates, then another dates, and another... After 30 tries for autumn or even next winter, the question is - are they that crowded or just some trouble booking them via common booking services?

Is it really possible to book them in advance?

Thanks for all replies.