The institution that makes the Shikoku circuit different from other long walks is settai: gifts given to henro by people living along the road. A mandarin, a coin, a can of coffee, a bed for the night, a lift over a pass. The convention is that settai is not refused, because the giver is not being kind to a stranger but acquiring a share in the pilgrimage. The henro is understood to be travelling with Kobo Daishi, so what is given to the henro is given to him, and the giver's merit follows the walker around the island. Refusing it takes something away from the person offering.
The walker's reciprocal obligation is small and precise: to hand over an osamefuda, the name slip otherwise left at each temple, so the giver has a record of the transaction.
The equipment carries the same logic. The white hakui is a burial garment, so the henro walks dressed for death. The kongo zue, the staff, is Kobo Daishi himself: it is washed before the walker washes, stood in the corner of the room rather than laid down, and never used to tap on a bridge, because the Daishi is said to have slept under one and the noise would disturb him. The phrase written on the hat, dogyo ninin, means two travelling together, and the second is not a companion.
The stamp book, the nokyocho, is filled at each of the eighty eight temples and is often placed in the owner's coffin.
Most henro now travel by bus or car, which the temples accept and the walking minority argue about, and the historical constituency of the road, which included the sick, the outcast and people with nowhere else to be, is not much discussed.