The electronics giant is holding its annual shareholders meeting tomorrow in Tokyo where the break-up plan devised by Daniel Loeb, head of hedge fund Third Point, was expected to feature.
But rather than seeking a public showdown with Sony's board, Loeb has opted for the soft touch with a hand-delivered letter that lauded Sony chief Kazuo Hirai's efforts at dragging Sony back to profitability.
Sony said it was reviewing the idea to sell off part of its entertainment unit, which includes a major Hollywood movie studio and a music label.
Hirai has resisted previous calls to break up the electronics behemoth which has struggled for years as it bled money from its television unit.
Loeb has a reputation for aggressively trying to force change at target companies. But he appears to be making a break from past investor confrontations with management, something which is rarely seen in Japan.
"Their (Third Point's) style seems different from so-called vulture funds in the past," said Hiroshi Sakai, chief economist with SMBC Friend Research Center in Tokyo.
"Third Point appears to be taking a long-term approach to gradually change Sony."
The Sony bid and a growing appetite for change among even some Japanese investors is setting off more constructive dialogue with management, said Tetsuyuki Kagaya, an associate professor at Hitotsubashi University in Tokyo.
"This is a quite flexible approach. Sony will have difficulty ignoring it," he said.
"It is getting more difficult for firms to have a management that completely ignores shareholders," Kagaya said.
"The era of activist shareholders is coming.