In my review of Rocket Japanese, I suggested learning the Japanese writing system before starting Rocket Japanese. Japanese has four alphabets, three of which are used interchangabely. The three which are used interchangeably are Hiragana, Katakana, and Kanji. The fourth alphabet is Romanji, which is basically writing Japanese sounds using Roman letters.
Hiragana is used for originally Japanese words, while Katakana is used for words which Japanese has adopted from foreign languages. Kanji are taken from Chinese, and there are tens of thousands of different Kanji in existence. However, the ones which it’s probably the most important top focus on learning are the Joyo Kanji. This is a set of 2,136 Kanji that a graduate of a Japanese secondary school would be expected to know.
The most basic Japanese alphabet to start with is Hiragana. This Introduction to Japanese course at Memrise starts off with a number of basic phrases in Romanji before moving through the Hiragana alphabet and introducing numerous words in it. The course asks you to set your keyboard to type in Hiragana at one point. However, I found it a lot simpler to simply use this keyboard at Lexilogos to copy and paste the necessary answers.
The next Japanese alphabet is Katakana. I started off with this two part course at Memrise to learn them, and then moved on to this course which has over 400 words in Katakana. All of the words are of foreign origin. Most of them are English, but there are some German and French words that Japanese has adopted.
The next alphabet is Kanji. Although it’s the most complex alphabet, this Kanji course introduces them in a simple order based on how they would be introduced to a native speaker. The first level starts with simple Kanji with a low number of strokes, like 一 for one, and gradually leads up to complex Kanji which have about 20 strokes.
Learning Japanese is a worthwhile goal, however, it won’t take overnight. It will probably take years, as it does for native speakers. It has the most complicated writing system in the world. Therefore, if you can master the Japanese writing system, you can master the writing system of any language.