Mochikaeri zangyō (持ち帰り残業): take-home overtime. Work that was not finished during working hours and is continued at home or in a café. An HR glossary by the company jinjer says it is also called furoshiki zangyō, wrapping-cloth overtime, because company documents are carried home.
The glossary adds that it counts as working time when the employer has instructed it, expressly or by implication.