Public domain
[Secret Records, Private Notes, and Other Items, Including Back-of-Paper Annotations of Calendars and Kana Calendar Fragments] [1]
From the collection of National Diet Library, Japan. Free to download, adapt and use — no permission needed.
Credit line[秘蔵記私鈔等並に紙背具注暦・仮名暦断簡] [1]. [南北朝-室町時代] [写]. National Diet Library, Japan. Public domain.