One of them is said to be the mastermind, who calls himself "Luffy" after a popular anime character.Philippine authorities deported two of them, Kiyoto Imamura and Toshiya Fujita, to Japan earlier this week.The other two - Yuki Watanabe and Tomonobu Kojima - arrived in Japan on Wednesday night.They were among dozens of Japanese nationals who have been arrested in the Philippines since late 2019 on suspicion of involvement in scam crimes.