national shrine of middle grade
Historical term from the Meiji-era shrine ranking system (近代社格制度). Refers to a mid-tier shrine under the direct supervision of the Jingikan (Department of Divinities) and later the Home Ministry, receiving offerings from the imperial court.
A kanpei chūsha is a shrine that was ranked as middle grade in the Meiji-era shrine ranking system.
Higher rank: national shrine of the highest grade.
Lower rank: national shrine of the lowest grade.
Middle-grade shrine under the supervision of the prefectural government, not the central Jingikan.
Compound of 官幣 (kanpei, 'imperial offerings') + 中社 (chūsha, 'middle shrine'). The term was created during the Meiji period as part of the modern shrine ranking system.