Ibaraki Prefecture Ōarai has a Humid continental climate (Köppen Cfa) characterized by warm summers and cold winters with light snowfall.

In 1928, Nisshō Inoue, the founder of the far-right militant organization Ketsumeidan (血盟団, League of Blood), relocated to Ōarai, where he established Risshō Gokokudō (立正護国堂, Righteous National Defense Temple), which served as a youth training center advocating a militarist revolution in Japan, eventually resulting in the 1932 League of Blood Incident.

Since 1998 the chief of a factory association in Oarai has invited Japanese descendants and migrants from North Sulawesi, Indonesia, to work for seafood industries.

The commercial fishing industry is important, and main fishery products include whitebait, sardines, flounder and clams.

Marine food processing includes salted and dried horse mackerel, smelt and sardines and boiled octopus.

Tourist attractions include bathing beaches, yacht and cruiser marina, marine sports, camping site, fishing, aquarium, and a famous golf course.

Real locations in the city are depicted faithfully, prompting fans to visit the town and giving a boost to local commerce.