Gaara

Gaara was introduced in the series in Chuunin Exams arc, as a violent shinobi from Konoha's allied country, the Wind country. He came to Konoha with his siblings Temari and Kankuro, and with his mentor Baki, to participate in Chuunin exams. From the first look, he was shown as merciless and violent individual. Due to his hard childhood, and lack of love, Gaara grew up hating everybody around him, loving only himself. In fateful incident about 6 years before the main story time, he made himself a tattoo of Japanese Kanji letter "Ai," which stands for "Love." In Gaara's case, that Love was for himself, as he was "Demon loving only himself." The Kanji "愛" for love that is on his forehead, is also part of his name.