The Embassy of Finland in Tokyo will be closed on Monday, the 12th of February due to a national holiday. The Embassy will open normally on Tuesday, the 13th of February.
The 12th of February is a national holiday in Japan. This is due to a system, where if national holiday falls on a Sunday, the next day becomes a holiday. The day before, the 11th of February, is National Foundation Day, which celebrates the foundation of Japan. In its current form, the holiday has existed since 1967.
Additional information on the holiday available here.