Is Duolingo enough?
Duolingo is really great but is it enough to get fluent in Japanese?
Duolingo is a good start, and in a lot of ways, it is better than a college. Completing a two year college course with straight A's doesn't make you fluent either, in any language. Consistency on the other hand, that is another story. I saw that someone gave you a down vote, and I strongly disagree. You asked a great question, that many people don't grasp. They start out on a path to learn a language, and then they become discouraged and quit. Fluency is a serious long term goal. If you're just starting out, you may want to lower your expectations a little and set goals that are more achievable in the short term, like learning hiragana, katakana, and a few kanji. When you get past that, move on to learning common words, later start on common phrases, etc. Eventually, you'll start to figure out if you are enjoying learning the language. That really is the key to becoming fluent. You need to like it enough to keep coming back. Answer the question for yourself, "Do I like the language I'm learning enough to keep coming back even if I won't be fluent for a long time." If you have the discipline and desire to stick with Japanese, then you will succeed. がんばてください！
Duolingo should be the equivalent of taking essentially level 1 of any language course at a local college. Although depending on the language you might get through a second course worth of material as well. You won't be fluent if you finish the course here by any means (especially as kanji is lacking). However, you should have a strong enough base to continue studying elsewhere at a higher level.
Also, keep in mind that Japanese is one of the hardest languages for an English native (or anyone with an Indo-European background) to learn and as such it will take a good amount of effort and consistency to succeed in but if you're passionate then by all means go for it.
Any course in Duolingo has something like one, two or three thousand words/characters to learn. This is a very basic level.
It'll give you a foundation that will help when learning via other means.
Duolingo will never give you fluency, even in its most extensive courses (spanish, french, german, etc).
Not even remotely, but you have to start somewhere. There's no app or software that's going to get you all the way to fluency.
You can still use software like Anki even when you're super advanced, but that's just because it's a generic spaced repetition software that doesn't have any specific content inside, you just review anything you put in it, so even ultra advanced material if you want, while with things like Duolingo you're limited by the content you find in there.
Duolingo is a good point to start when it comes to learning a language - But it's not enough for you to learn speaking a language fluently. It will just give you a base, so you can start off not by the beginning, but rather with a base, when taking a Japanese course in real life for example. Since things like Kanji are lacking in the Japanese courses, you definetly won't be a fluent speaker afterwards. But it's a good help on your way to become one
Konnichiwa! I feel the same about Duolingo. One program that I can't recommend highly enough (as I've told a bunch of people hehe) is Rosetta Stone. It uses the natural way you learnt your first language by showing you a picture of an object or basic action (paper, apple, bicycle; running, eating, sleeping, etc) and telling you only the word for it in the new language. There's no translation from, say English, to the new language.
After you've learned the basic words, then the program uses this foundation to introduce you to simple sentences etc and on to more and more complex things as you progress. The great thing is that it uses reading, writing, listening and SPEAKING in only the language you're learning to teach you.
It has specific lessons for grammar and uses a variety of ways to get you speaking, from speaking what is written in front of you and what is spoken to you all the way to spontaneous speech without any guidance. The speech recognition thingy analyzes your pronunciation and will tell you if you're wrong and help you correct it. The speech aspect is great for introverts like me, who forgets everything I've ever learned whenever I have to actually speak the language to an actual person.
It gets you learning and confident in speaking the language before you have to talk to someone. I have now been studying Spanish through it for about a year and a half now. It's the best thing I've ever run into, and if you don't mind spending some money to get really good quality learning, then what's stopping you? Knowledge is power, after all. P.S. Go read the comments for and the post Why Duolingo Will Never Teach You A Language. It's on the New page on All Topics and I think it might help you a lot!