I didn't say that's how it works I'm just giving perspective and Microsoft does indeed have enough to buyout Sony if they wanted.(If Sony was even willing to sell in the first place.)
The part in the bracket is the important part here.
You should at least explain your reasoning why.
Bill gates could buy Sony and Nintendo.
You can't just come in and 'buy the company'. First off we need to figure out what is actually meant by buying the company? Do you want 50%? maybe 75% just to get special resolutions passed as well? Or do you go with a complete hostile takeover for a 100% ownership of the company?
Then you need to start buying up the shares. You're not buying them from Sony. You're buying them from other shareholders. Do they want to sell them to you? Many might, but many might not. With the current trend of Sony shares I think many will want to retain the shares for a bit longer unless a really good deal came up.
There is your third uncertainty. You most likely won't be buying the shares in bulk for the market price. As I've said the current trajectory of Sony's shares is going up so many would want you to pay a higher price for the share if they were to part with them. As soon as you'd start hoarding shares though, and by this I mean having 5% of the company, the other shareholders will quickly realise that you're wanting to buy up the property. In fact with MS buying Sony's shares this would be all over the news. So the shareholders will hike-up the price simply because they know you want to buy up the company.
The fourth uncertainty lies with the management. As soon as they'd get the wind of MS buying up they would no doubt try to either buy up a considerable shareholding themselves so that MS would not have a controlling majority or try to dilute the shares. Now that isn't strictly legal but it could be easily believable that Sony issued new shares to raise capital given their situation.
Fifth hurdle to overcome in this case would be the Japanese governnment that is incredibly protective of its tech giants. Should the news of MS trying to buy up Sony become public knowledge you'd no doubt see the Japanese Central Bank buying up Sony's shares to prevent MS's to achieve a controlling majority in the company.
The shareholders might not be too happy about allowing MS in either. They can only alter their Articles of Association to give a first right to buy to existing shareholders should any other shareholder decide to sell its share, effectively being in control of who's buying up the shareholdings. In fact Sony might already have this clause (I don't know). Another effective way of protecting the company's interest would be to give the directors the right to decide whether or not to register the shareholder as he would become a member of the company. Usually the ground given for not doing so would be the fear for the company's best interests.
This is not even mentioning the Japanese government not agreeing to this during it's anti-competition investigation.
