Fr Hamaguchi was born in Sasebo (Nagasaki) on 1 May 1958, and joined the Salesian Novitiate 1981-1982 in Chofu (Tokyo), made his first profession on 25 March 1982, and his perpetual profession on 19 March 1988 in Chofu. After his ordination, in Tokyo on 23 September 1990, he dedicated much of his ministry in youth social work, the “Boys Home” in Kodaira (Tokyo) for 14 years.
Then he was assigned to assisting Salesian Bishop Francis Osamu Mizobe in his challenging assignment in the Takamatsu diocese with other Salesians (2005-2009). Since 2010 he has been committed to formation in Chofu (2010-2018). Last 1 April he was assigned as Rector of Meguro community in Tokyo (parish, kindergarten and youth center).
Since 2015 Fr. Hamaguchi has also served as the Vice-provincial and Delegate for Formation, even if since last February Fr. Michael Lap is the Formation Delegate. Since last April 2018, Fr. Hamaguchi has begun his new role as Youth Ministry delegate.
Under the former provincial Fr. Hamaguchi was also a Coordinator of the PROJECT TEAM, an ad hoc commission in charge of the ongoing reshaping process at the provincial level. The main focus is the province's poor young people and to empower the lay mission partners with Salesian formation.
Hamaguchi will succeed as GIA Provincial to the Bishop Elect of Saitama, Fr. Mario Yamanouchi.