Untoan is an ancient Soto Zen temple where, by tradition, both Uesugi Kagekatsu and Naoe Kanetsugu studied in their youth. The temple lies close to Uonuma, Kanetsugu's birthplace, and has long been revered as a place of deep local connection to both men. The tradition that the extraordinary lord-retainer bond between them was first forged here continues to draw visitors who regard it as the spiritual starting point of their lifelong partnership.

Untoan Temple was the school of Uesugi Kagekatsu and Naoe Kanetsugu, the two men who would carry on the Uesugi legacy after Kenshin's death. Kenshin raised Kagekatsu (his nephew and adopted son) and sent him to be educated at this renowned Zen temple. The motto 'Have you trodden the soil of Untoan?' captures how celebrated the temple's learning was across Echigo, and the training received here formed the backbone of the post-Kenshin Uesugi.