We have found a large amount of 6Li in the atmosphere of the star HD 82943 which harbors two planets. From the amount of lithium in the star's atmosphere, we infer that there was a third planet (or several planets) that died in the hot interior of the star. The star could have swallowed a planet with a mass of about 2 Jupiters or 3 Earths. Based on our original publication (Israelian et al., 2001), here we introduce the several features and background motivation of this study to the general readers in Japan.