Monto is a name one uses for comrades of the same sect. Particularly, it indicates the people who belong to the same school and share the same belief. It has also come to indicate the danto (supporters) belonging to a temple.
Especially in Jodo Shinshu, it is general to call danto and believers 'monto,' but it's rare that one would refer to the danto of other Buddhist sects by that name. Consequently, 'Jodo Shinshu' is sometimes called Montoshu.
Occasionally, the word is used with the names of regions, like calling the monto of XX region as 'XX monto.'
(Examples: Mikawa no kuni monto (monto of Mikawa Province), Aki no kuni monto (monto of Aki Province, and so on)).
In "Hoonkoshiki," by Kakunyo: 'Always talk to monto.'