With hard work, commitment and determination, I think it is possible. The concept of fluency is not concrete though. It depends on what you would consider fluent; whether you can get by in every day conversations or be able to understand and express everything without error. Usually the individual determines fluency for himself. As for myself, I consider fluency to be the ability to communicate relatively effortlessly. You may not understand EVERY word that is said to you, but you understand general concepts and are able to describe what you don't know and want to know. That, I think, is possible to do in one year. Use the grammar as your scaffold and build vocabulary onto that.

I know an Indian guy whose native language is Tamil. He is fairly fluent in Japanese, but he isn't still good at written Japanese. If you focus on conversational Japanese at the moment, I would say it's possible. A lot of Indian people residing in Japan speak Japanese with clear accents. In addition, each grammar rules have some similarities. It's because both of them are agglutinative languages. However, it would be a pain in the neck to master regarding written Japanese. If you have any question about Japanese, feel free to contact me. Keep up the good work.

Anything is possible, but it would take an incredible amount of dedication. Bear in mind that "learning Japanese completely" is not really the right question to ask, because once you have the 2 basic writing systems understood, you move onto grammar, and then Kanji ( which there are over 2000 in daily use). So in order to become fluent, you'd need to be immersed, and learn roughly 2000 Kanji outside of grammar and hiragana and katakana. There is a video I found on Youtube the other day where someone studied Japanese, hardcore for 1 1/2 years and his wife used Google Translate to see which was better, and he was able to function remarkably well. So in short, I doubt you'd learn ALL of Japanese, it'd be hard enough to become properly conversational. I'd say 3-4 years would be ideal given daily use. Language is a very long process, there are no quick fixes to mastering an entire language in such short time. Life isn't like the Matrix, where it can be simply uploaded. It takes time, trial and error, experiences, interactions, comprehension, cultural studies, and many more to properly become fluent.

If you do two things it would help: 1. Immerse yourself in Japan and talk to many people each day in Japanese. 2. Lower your standards. Be satisfied with speaking as a child. That my $0.02

I don't think so. Japanese is not an easy language to learn. Actually, I hardly see a person who can speak fluent Japanese in a year.