If the problem of sex was uppermost in the Venerable Master’s mind at the age of 29, he could have had a clandestine affair as many monks at the time were doing. But one of the reasons the Venerable Master left Mt. Hiei was because the monks were not keeping the Buddhist precepts, among which is not engaging in sexual activities.
I believe the Venerable Master determined to marry because of the revelation by Kuse Kannon of Rokkaku-do. As indicated in the following passage from the Wago Toroku (A Record of the Light), Master Honen said that we should live in whatever way allows us to recite the Nembutsu:
Recite the Nembutsu to get along in this world. It makes no difference what you do as long as it does not obstruct reciting the Nembutsu. If you cannot recite the Nembutsu by abandoning the world and becoming a monk, then take a wife. If you cannot recite the Nembutsu while married, then abandon the world. If you cannot recite the Nembutsu while settled down, then recite while wandering from place to place. If you cannot recite the Nembutsu while wandering, then become a householder.
As indicated in the above passage, Master Honen said that if we cannot recite the Nembutsu and remain celibate, then we should recite it while married; that if we cannot recite the Nembutsu while married, then we should recite it while celibate.
Master Honen himself remained celibate all his life but he did not say everyone should follow his example. The Venerable Master must have heard Master Honen say similar things, and very likely affirmed a married life for himself.
The Venerable Master’s spiritual life must have deepened while living the life of an exile in the deep snows of the remote area of Echigo Province, surrounded by a wife and children, and associating with the people of that area.
On the 17th day of the 11th month during the 1st year of Kenryaku (1211 AD), when he was 39 years of age and five years after reaching his place of exile, the Venerable Master and Master Honen were pardoned. The Venerable Master very likely intended to return to Kyoto, but on the 25th day of the 1st month of the next year (1212 AD), just two months after their pardon notices, Master Honen passed away in Kyoto at the age of 80.
The Venerable Master apparently gave up any thought of returning to Kyoto after learning of Master Honen’s death. He remained in Echigo province for some time after being pardoned, but during 1214 AD, when he was 42 years of age, he left that area with his wife and children for Shinano Province (present-day Nagano Prefecture). He then moved to the town of Sanuki in Kozuke Province (present-day Gumma Prefecture), and from there to Hitachi Province (present-day Ibaraki Prefecture).
In Hitachi Province, the Venerable Master made towns such as Kojima and Inada his base, and spent the next twenty years spreading the Nembutsu teaching. This activity resulted in a large number of disciples and followers. He had about 80 direct disciples. If those who were disciples of his direct disciples are counted, however, his followers can be considered to have numbered in the tens of thousands.
But as the Venerable Master is quoted as saying in the Tannisho, however, he did not consider himself to have any disciples:
I, Shinran, do not have any disciples. The reason I do not is because people recite the Nembutsu through the workings of Amida Buddha and not because of any efforts on my part. It is thus ridiculous to refer to those who recite the Nembusu as “my disciples.”