Four Japanese tycoons have been named by Forbes Asia to its list of Asia's top 48 philanthropists this year, the business magazine said Thursday.

They are architect Tadao Ando, Suntory Chairman Nobutada Saji, Softbank Chairman Masayoshi Son and Fast Retailing Chairman Tadashi Yanai.

Forbes Asia said the March 11 calamity "has weighed heavily on the minds of Japanese billionaires."

It mentioned that Son has promised to donate ¥10 billion to support and educate children left without parents after the earthquake-tsunami catastrophe and pledged to turn over his salary, estimated to be around ¥100 million for the 2010 fiscal year, until he retires.

Saji's firm gave ¥300 million to relief efforts immediately after the quake and has said it will also donate ¥1 for each sale of its canned beverages, with the expected proceeds of some ¥4 billion to be channeled to the purchase of new fishing boats, and educational and cultural projects.

As for Yanai, aside from donating millions of yen in clothes and cash, his company is helping to launch a line of T-shirts with profits going to the Japanese Red Cross Society for recovery work.

John Koppisch, senior editor of Forbes Asia, said the magazine's goal is not to rank the biggest givers by monetary amounts, but instead to call attention to "a mix of notable people and causes throughout the region, and to encourage more giving."