Mao Asada (Qian Tian  Zhen Yang , Asada Mao, born September 25, 1990) is a former Japanese competitive figure skater. She is the 2010 Olympic silver medalist, a three-time World champion (2008, 2010, 2014), a three-time Four Continents champion (2008, 2010, 2013), and a four-time Grand Prix Final champion (2005-06, 2008-09, 2012-13, 2013-14). She is the only female figure skater who has landed three triple Axel jumps in one competition, which she achieved at the 2010 Winter Olympics.

During the summer of 2007, Asada received additional training in Russia from Tatiana Tarasova, while Arutyunyan remained her primary coach. At the 2007 Skate Canada International, Asada was third in the short program and first in the long, finishing with the gold medal ahead of silver medalist Yukari Nakano. Asada won her second gold at the 2007 Trophee Eric Bompard with over 21 points ahead of silver medalist Kimmie Meissner.  Asada advanced to the 2007-08 Grand Prix Final in Turin, Italy. In the short program, Asada did not do the jump out of footwork required element and placed 6th with a score of 59.04 points. But the next day, she rebounded in the free skating to win the free skating with 132.55 points. She executed a triple axel, a triple flip-triple toe loop combination, a triple loop, a triple flip-triple loop, a double axel-double loop-double loop combination, and a double axel, but had a change-of-edge error in triple lutz. She won the silver medal with 191.59 points, 5.24 behind gold medalist Yuna Kim, who repeated as champion.  As in the previous year, Asada won the 2007-08 Japan Championships. Her final score was 1.15 points ahead of silver medalist and reigning World champion Miki Ando. Asada was placed on the Japanese team for both the World and Four Continents Championships. Before Four Continents, she split with Arutyunyan and returned to Japan to practice on the new Aurora Rink at Chukyo University, where she had no problems obtaining ice time.  Asada competed at both ISU Championships without a coach but an official from the Japan Skating Federation accompanied her as needed. Competing for the first time at Four Continents Championships, Asada won both segments and finished 13.71 points ahead of silver medalist Joannie Rochette. In March 2008, at the Worlds Championships, Asada won her first World title. She was second in the short program, 0.18 behind Carolina Kostner. In the free skating, she was second to bronze medalist Yuna Kim by 1.92 points but 0.88 ahead of silver medalist Carolina Kostner.

Using a quote from the above article, answer the following question: When did she return to USA ?