Today Hiragana is the writing method of choice for all of Japan. However, at the time of its creation hiragana was contending with another form of writing Chinese. Before hiragana was created in the 8th century Chinese characters were the only choice of writing style. This is becuase before the chinese writing style there was nothing else. When the chinese written language showed up the Japanese thought that they could just take the Chinese characters and use them for Japanese. However, they soon discovered that this was inefficent and had to adapt some of the Chinese characters to fit their needs. This adaptation slowly transformed itself to hiragana.
Korean Hangul was created as a replacement writing system for the many adaptations of Classical Chinese that were used in 15th century Korea. In approximately 1440 B.C.E. King Sejong the Great had a group of scholars create a writing system to better fit Korean phonetics, the result of their work was Hagul. It is a phonetic language consisting of 24 letters which are aranged into syllable blocks, which are read as words, and read from left to right. Despite being created in the 15th century it didn't see widespread use until the mid 20th century.
The Chinese writing system is the most influential system used on the Asian continent. Originating from the use of oracle bones, Chinese characters have been used for thousands of years and have widely impacted the Korean and Japanese written languages. Unlike, Western languages which use an alphabet, the Chinese writen language is composed of thousands of symbols that have their own independent meaning, called characters. Moreover, caligraphy evolved from characters and was used by scholars and artists to express one's own style and feeling. Over it's thousands of years of use, Chinese characters have experienced a long evolution, with the most recent change (simplification) in the 1950s.