The Western Mino Group of Three refers to three retainers of the Mino-Saitō clan during the Sengoku period, namely, Inaba Yoshimichi, Andō Morinari, and Ujiie Naomoto.  The name of the group derives from the location of their residences and landholdings in Mino Province.  The group name applied after the time of their submission to Oda Nobunaga and the term may have been a twist on the name of another group, the Miyoshi Group of Three (Miyoshi Nagayasu, Miyoshi Sōi, and Iwanari Tomomichi) which was formed before this group.

Most the materials regarding the Group of Three are based on records, military chronicles, and genealogies compiled in later eras.  In historical documents, there are numerous accounts of the Inaba clan but relatively few in regard to the Andō or Ujiie clans.  All members of the Group of Three came from ancestors residing in Mino for several generations who served the Toki clan.  After the demise of the Toki clan, these families affiliated with the Saitō clan in Mino.  The members of the Group of Three are known to have served as chief retainers of Saitō Yoshitatsu during the Eiroku era (1558 to 1570) when Oda Nobunaga held sway in Mino.

On 8/1 of Eiroku 10 (1567), the Group of Three defected from the Mino-Saitō clan and joined Oda Nobunaga.  In 1567, Nobunaga allocated to the members of the Group of Three one-third each of the spring and fall taxes and compensation generated from the area lying to the west of the Kuise River.  This is deemed to have been a reward for the actions of the Group of Three to betray the Saitō and collude with the Oda.  While serving the Oda clan, in the ninth month of 1568, the Group of Three participated in the march upon Kyōto by Nobunaga and participated in numerous battles in pursuit of Nobunaga’s plans for a national hegemony.

In 1571, during the Nagashima Ikkō-ikki ((attacks by Oda Nobunaga against followers of the Hongan Temple in Ise-Nagashima that ran from 1570 to 1574), Naomoto was killed and succeeded by his son, Ujiie Naomasa.  In the eighth month of 1580, upon orders of Nobunaga, Andō Morinari was convicted of crimes and banished so the Group of Three was extinguished.  In the background, the removal of Morinari may also have been planned by Nobunaga in an effort to reorganize the militaries in Mino and Owari under the command of his lineal heir, Oda Nobutada.  It is also noted that Morinari was a former archrival of Nobunaga and, with Mino and Owari serving as key provinces for Nobunaga, the presence of Morinari who was expanding his power in Mino was unsettling.

After the coup d’état in the sixth month of 1582 that resulted in the death of Oda Nobunaga, Yoshimichi subdued former comrades such as Andō Morinari and Andō Sadaharu.