Japan and the United Kingdom have highly developed industries and advanced technologies. The level of GDP in these countries is among the highest in the world. Traditionally, intensive business activity takes place between these countries, which, certainly, entails increasing popularity of the GBP/JPY currency pair on the forex market.
It is really hard to forecast the GBP/JPY chart, as the pair is highly susceptible to a variety of economic and political events in the world. On the chart, strong price spikes often take place which could negatively affect current open positions.
Working with such a financial instrument, it is necessary to analyze a large number of facts and peculiarities of the chart behavior which first could seem insignificant. Newbies are not recommended to use the GBP/JPY instrument.  
The U.S. dollar has a great influence on each of the currencies of the given pair. Its exchange rate should be taken into account. In addition, a trader should pay attention to the major U.S. economic indicators. If we combine the charts of GBP/USD and USD/JPY, then we will get an approximate GBP/JPY chart, and could estimate the U.S. dollar's influence on the pair.