Loamanu's grandfather Tevita Sitanilei played scrum half for the Tongan national rugby union team, whilst his brother Sitani has played for the Tongan national rugby league team.

[3][4] A few days after his second cap against Hong Kong, Loamanu was banned for a year from the Japan team after getting embroiled in a fight involving female professional wrestler Mika Akino in Tokyo's Roppongi nightspot district.

[5][6] He was recalled in 2007 and scored a hat trick on his return to the side against Korea and he played at the Rugby World Cup later that year.

He joined Toshiba Brave Lupus in 2008 and won the Top League with them, but in February 2009 Loamanu tested positive for marijuana and was banned for life from playing rugby in Japan by the JRFU whilst his club Toshiba Brave Lupus withdrew from the All Japan Championship after the incident.

[1] In May 2014, Loamanu has signed for English club Leicester Tigers where he will compete in the Aviva Premiership from the 2014–15 season.