In the context of this shrine, “cloister” means monastic house. More generally, the word refers to enclosures, which is how it can elsewhere refer to an enclosed garden or to an enclosed courtyard.
@Oeconomist i see.... see, what i did was i googled "kibitsu shrine cloister" and the result "400m cloister" showed up, and because i'm not very smart with vocab, i just went with it. welp. today i learned