The hanzi/kanji is almost the same, but Japanese uses the traditional form, whereas you may see the simplified in the PRC. A very, very beautiful character. Currently trendy on teenybopper/raver clothing, platform shoes, and so on. Unfortunately.
Ai is also a kind of sloth, of the genus Bradypus. Ais are differentiated by their having three toes from sloths of the genus Choloepus, who have two. Other differences include number of vertebra (three toed sloths have nine, two toed ones six or seven) and tails (ais have them).