The pillar of Japanese writing
Kanji are written characters of Chinese origin that make learning Japanese complicated, but so much more methodical.
Japanese and kanji
In elementary school Japanese children learn more than a thousand kanji, and this is just the beginning. However, the Japanese will still come across words they can't read or write throughout their lives. Ones that aren't used every day are quickly forgotten, especially nowadays when we don't write by hand as often. It's not uncommon to see Japanese television programs in which guests (often graduates of prestigious universities) must find the readings, detect errors, or guess the meaning of unusual kanji they are presented with.
Lastly, surnames and forenames remain the most difficult aspect of kanji to master. Even though there are many common names, you must be wary because some people who have the same combination of kanji in their names won't pronounce it the same way, and the Japanese are increasingly likely to choose more unusual readings of kanji for the names of their children. This makes the task even more difficult if, for example, a Japanese colleague gives you his business card. This doesn't mean that you have worry, because the reading can be clarified in person.