Hostile takeovers and ways to repel them are the hottest topics in Japan's corporate boardrooms these days.

Internet firm Livedoor Co.'s success in gaining a majority stake in Nippon Broadcasting System Inc. -- a step toward gaining control of Fuji Television Network Inc. -- is making daily headlines and is a nightmare come true for many executives nationwide.

Some are scrambling to put in place poison-pill defenses against similar unsolicited attempts on their firms. The targeted firm, in such a case, usually would attempt to issue a large amount of new shares to dilute a bidder's stake.