The first influence of this kind of the thing is the arms race. In the case of weapons they are always racing against armour.
Japanese weapons evolved to the point where they were able to defeat the type of armour they would encounter and Western weapons did the same.
Due to the increased diverity of cultures, greater natural resources, farming technoologies (along with a long East West latitude), specific attitudes towards war and other considerations the arms race progressed far quicker in Western than in Japan. Weapons and systems evolved to work against full plate, cavalary etc. In Japan massed cavalary charges were rarer, armourer (esp full plate) was rarer and not as protective due to cultural and resource reasons.
Therefore Western and European battlefield tactics were not solving the same problems.
However, in terms of dueling they had more in common. The style have several simularities but this is mainly because there are only so many ways one can use a sword and warriors in both regions found them fairly quickly. I teach medieval armed combat and have taken various courses in Japanese styles. There are some differences but there are also differences between different Western schools of combat.
However, by the time Europe gained access to Japan and the Japanese saw European technologies and culture the time of swords and hand held weapons on the battlefield was largely passed and the Japanese quickly imported firearms and experienced teachers in order to update their military as quickly as possible so it is unlikey that there was much direct influence from Western sword fighting to Eastern