Your example does not match your question.
In your question, you ask:
Then, in your example, both your BUY and your SELL have the same quote currency (JPY):
In order to answer your question about conflicts, I’ll have to answer it twice: once in the context of your question (above), and once in the context of the example you gave.
• First, based on your initial question, in which a currency is the QUOTE currency in your BUY, and the same currency is the BASE currency in your SELL, let’s use the following scenario:
Let’s say you BUY one lot of EUR/USD, and SELL one lot of USD/CAD. In effect, you BUYING the EUR/USD and you are also “BUYING the CAD/USD” (using the inverse of the standard USD/CAD pair, in order to make a point).
These two positions are USD-correlated – meaning that together they double the impact of any strength or weakness in USD. This may, or may not, be a “conflict”, depending on your intent in these trades. But, if this correlation is unintentional, you should take steps to avoid it.
• Second, based on the example you gave, in which JPY was the QUOTE currency in two different positions, you have another case of correlation. This time, your two trades are JPY-correlated – meaning that together they double the impact of any strength or weakness in JPY. The caution regarding unintentional correlations given above applies here, as well.
• Finally, if you trade through a U.S. broker, you are prohibited from entering any trade defined as a “hedge”. That would be a trade in which you have a LONG position and a SHORT position in the same currency pair. For example, if you BUY one lot of EUR/USD and then sell one lot of EUR/USD, your SELL will cancel your BUY, leaving you with no position. In the U.S. such a hedge clearly “conflicts” with the rules dictated by the regulator.
In other countries, where hedging is not outlawed, some traders insist that it makes sense to hedge certain positions in certain situations. However, other traders (myself included) would argue that a hedge represents an inherent conflict, in that each position cancels the profit (or loss) in the other position.