Japan probably does not strike you as being a very interesting place to travel to as a tourist. The modern industrial complex of the country and the fact that much of the traditional rural areas are devoid of life makes the cost of the trip not especially appealing to those not accustomed to what is available. Surprisingly, as mentioned in an article from Forbes (https://www.forbes.com/sites/anismuslimin/2018/04/04/japans-richest-2018-tourism-takeover/#e4a95f8554a1), Japan is actually seeing a massive increase in tourism lately, to a degree that it may be able to significantly boost the economy of the country and move it into a new period of national prosperity.
The main sights of Japan to see are the traditional architecture and culture that the country still provides. Japan itself is a vibrant combination of new and old, which is unique to the country as it was forced to modernize from a feudal society of sword wielding warriors into one that used railroads and muskets within a time span of roughly twenty years. This unique perspective makes the cultural landscape, mannerisms of the Japanese people, and tourist locations especially interesting to tourists from the West.
One of the most popular sights to visit in Japan is the old capital city of Kyoto. Kyoto at one point in time was the seat of the Emperor and had been for hundreds of years. The city to this day represents this rich historical background with its elaborate Buddhist and Shinto temples. Japan is quickly becoming the place to go for Western tourists.