Considering it their responsibility as rulers to learn about the traditions, customs and systems of their subjects, the colonists launched a large-scale collection of old contracts in 1900.
明治卅三年（一九○○年），當時的日本統治者認為要統治一個地方必須要充分瞭解它的民俗、習慣、制度，因此大規模地蒐集民間古契約。