Unganji is a temple of the Rinzai sect of Zen Buddhism. A temple was first established on this mountain in the 12th century and at one time it was a great religious center with more than a thousand priests in residence. Later, the complex was burned by Toyotomi Hideyoshi, but reestablished during the reign of Tokugawa Iemitsu.

Butcho was a Zen teacher who had earlier given Basho instruction in Zen Buddhism. He had been born at Kashima in 1640 and at the age of eight entered the Konbonji Temple to study under the guidance of Reizan. He was 35 when Reizan died and expected to succeed his master as head priest of the Konbonji, but was rejected for this position by the abbot of Kashima and the temple's stipend was slashed. Consequently, Butcho went to the Shogun's court in Edo to plead his case. In 1678 he accepted a position as priest at Unganji, but in 1682 he won his suit and his position at Konbonji was restored. He died in 1715 at the age of 76. Apparently he had been Basho's teacher during the time he spent in Edo pleading his case.

In the poem describing his hut Butcho makes the point that his dwelling is so insignificant that he would not even bother with it except that it sometimes keeps off the rain. This reflects the attitude of Kamo no Chomei and of Basho who both rejected the idea of permanent dwellings. At 5 shaku this hut is half the size of Chomei's.

For Basho this passage describes a particularly meaningful and personal visit to the site where his master came to terms with religious truth. Basho's single-minded intent is to see the place where Butcho meditated, but he creates a tension by showing us also how many distractions there were. He meets a throng of other travelers, especially a group of boisterous young people, but he gradually draws away from them, first up a narrow valley, then through a gate, and finally across a bridge leaving the world completely behind. And when, at last, he reaches the temple, he ignores it and goes around behind it to seek out the ruins of Butcho's hermitage. Along the way, in addition to the boisterous travellers, he makes an elliptical reference to the ten famous sights and the five famous bridges of Unganji, a rich environment for the tourist, but he ignores it all in favor of the ruined hermitage which he seeks. The bridge he crossed is the Katetsukyo Bridge, one of the five famous bridges of Unganji. The gate he passes through is the Sanmon Gate, an especially sacred one that protects pilgrims. Normally Sanmon means "mountain gate" and refers to the outermost gate of a Buddhist temple, but a homophone can have it mean "triple gate," that is, one that protects the pilgrim from 1) covetousness, 2) anger, and 3) silliness.

Not only is a contrast established between the worldly distractions along the way and the holy and personally significant site that Basho seeks, the natural setting also provides a contrast. The narrow valley with the dripping moss has a chill, fresh sense about it which is in contrast to the time which is the Fourth Month, a time usually associated with the beginning of summer. The natural landscape belies what the calendar tells us about the season. This enables Basho to contrast the warm, livliness of the fellow travellers with the lonely isolation of the detatched hermitage, now fallen into ruin and forgotten by everyone except Basho, the disciple, seeking traces of his master.

Having located the ruins of the hermitage, Basho is reminded of great hermit-priests of the past, Gemmyo and Houn. Gemmyo was one of the great Zen priests of Sung China. He was born in 1238 and left home at the age of 15 to enter the priesthood. Eventually he secluded himself in a rock cave where he remained for 15 years while many disciples came to receive instruction. Over the mouth of the cave hung the inscription "Shikan," The Gate of Death. The sense of this is that by entering the cave he had cast away his life in the world and by staying in the cave remained uncontaminated by worldly influences. Houn was regarded as one of the three great priests of the Liang dynasty. He built his hermitage on an isolated stone and it is said that until the end of his days he never tired of disputation and debate of religious questions. He died in 529 at the age of 63.

Basho's poem expresses his feelings on seeing his master's hermitage; celebrating the virtue of Butcho and expressing Basho's sense of yearning and regard for his former teacher. The woodpecker, "Kitsutsuki" is also called "Teratsutsuki," Templepecker. The legend is that the angry spirit of Monobe Moriya became a woodpecker and used his beak to try to destroy Buddhist temples. The sense of the poem is to ask the woodpecker to refrain from the sacriledge of damaging this august hermitage which has already gone to ruin. There is a sense here that the place is so dilapidated that even a woodpecker could bring it down. The image is this: the summer trees are so full of foliage the place is dark even during the day, it is lonely and no sound is heard until from far off comes the sound of the woodpecker. Here in these deep, lonely woods is an old, dilapidated hermitage. The poet asks the woodpecker to leave it alone.

According to Sora's diary Basho's activities while at Kurobane were to visit Unganji on the 5th, Komyoji on the 9th, while on the 12th they went sightseeing on Nasu Plain, and on the 13th they visited the Kanemaru Hachiman Shrine. Basho has altered this sequence to place the visit to Unganji last, probably because he felt it was the most important event. This ancient mountain temple evidently appealed very powerfully to him, in part because of its associations with Butcho.