The Japanese do their best when it comes to learning English, with most taking six years in junior high and high school, and up to ten years if they take it in university. But although many master reading and writing, speaking it well can be another matter. Some of our words seem to be custom-made to frustrate poor Japanese ESL learners, and there are many categories of words that are as hard for them to pronounce as the hardest French words are for English speakers. Japanese famously lacks differentiation between L and R, and I had a Japanese friend who refused to discuss politics because she knew that sooner or later she'd have to use the word "election" and feared embarrassing herself. Nothing is harder for Japanese to pronounce than words that combine both L and R sounds, like jewelry, parallel and vocabulary, and words where the vowel is basically an "rrrr" sound, like girl, world or the last syllable of computer are also challenging. The big test for any Japanese student of English is, do people understand them when they go abroad, and all too often the answer is no, as in the case of a former student who asked for water in a restaurant and was brought a glass of beer. My wife does her best with English but sometimes life can be cruel: J-List's San Diego office has an employee named Marissa, and I have a niece named Melissa, and my wife never knows which person I'm talking about.
The Japanese study "How to English" but pronunciation is hard.