A stone tablet at Uozu Oomachi Private Elementary School bears this inscription, which was a tanka poem composed by Uesugi Kenshin at Uozu Castle.

Since the poem was originally spoken, there are several written versions:

もののふの鎧の袖を肩しきて 枕に近き初雁の声

武士のよろいの袖をかたしきて 枕に近きはつかりの声

武士の鎧の　袖をかたしきて　枕に近き　初かりの声

武士の鎧の袖を片敷きて枕にちかき初雁の声

One possible interpretation is

"The warrior makes
Of his armor a pillow
For his head alone:
A solitary repose.
The first wild geese cry nearby."

"A pillow for his head alone" refers to the practice of lovers rolling their garments together to make a pillow for two. The "first wild geese" is oft-used imagery implying the approach of autumn and winter, the months these birds fly south from the Siberian regions to spend in Japan. Of course, they may in turn imply the autumn and winter of a person's life...

The first version of the poem, which is rather rare and the one used by Kuwabara-sensei in Mirage, implies more of a "carrying" or "shouldering" than a lying down; it may perhaps be interpreted as "The warrior shoulders his armor, though the first wild geese cry near his pillow."