Hi @Takuto_Suzuki,
Do be careful, though - stories are not meant to act as an audit trail and don’t necessarily contain a 100% complete record of changes, for two reasons: first, any story can be deleted by a user via the Asana web UI; second, Asana’s architecture includes a behavior known as “story consolidation”: if multiple changes to a particular property of a particular object are made by the same user within a 24-hour period, without any intervening changes to that property by another user, then only the last story is kept, the preceding ones are removed.