Sept 16 (Reuters) - Japanese shares received massive foreign inflows in the week ended Sept. 10 as hopes of a stronger government and expectations of fresh economic stimulus boosted investor optimism.

Foreign investors bought Japanese equities worth a net 1.07 trillion yen ($9.79 billion), which was their largest weekly net purchase since Nov. 13, data from Japanese exchanges showed.

Investors purchased 756 billion yen worth of derivatives and 301 billion yen in cash equity markets.

Cross-border investors purchased Japanese bonds of net 644.9 billion yen, their third straight week of net buying, finance ministry data showed.

The rally in Japanese shares gathered pace since Sept. 3 when Prime Minister Yoshihide Suga announced his plans to step down, strengthening the position of the ruling coalition for an upcoming election and bolstered hopes of a new stimulus package.

Last week, Japanese shares closed higher for a third straight week. The Nikkei share average surged 4.3% and the Topix index added 3.8%.

Shares hit a three-decade peak this week, but retreated since the mid of the week as investors locked in profits.

Japanese investors sold a net 139 billion yen in overseas equities, that marked their third straight week of net selling, but bought a net 1.72 trillion yen in foreign bonds last week, finance ministry data showed.

($1 = 109.3200 yen)

(Reporting by Gaurav Dogra and Patturaja Murugaboopathy; Editing by Sherry Jacob-Phillips)