Rōmon

Rōmon [亭询; ろうもん] is the last shrine or temple visit of the year. It usually occurs in the last week of December, around seven days before the first visit of the New Year, known as kanmon. This visit is generally considered much less significant than kanmon and places of worship observe much lower numbers of visitors.
Generally, rōmon entails a brief period of worship or prayer inside a temple or beside a shrine, often asking spirits to forgive any sins committed over the last twelve months. Repentance and promises of resolution are common. In some regions, children are encouraged to write letters of gratitude or apology to their older family members to make up for any bad behaviour, or simply to express appreciation for the hard work of their elders.