Kazura was selected as the winner on a lottery that he bought on a whim, and received 4,000,000,000 (4 billion) yen.<br />To evade the hyenas that smelled the scent of his money, Kazura took refuge at an old residence that had been handed down from generation to generation in his family.<br />When Kazura was investigating the place that would become his shelter, he stumbled on a certain room where it was possible to go into and back from another world.<br />The culture and technology level of that world was relatively low. The protagonist sometimes brought goods, sometimes brought technological knowledge.<br />At that world, he would find his true value as a person.<br /><br />Source: http://comic-walker.com/contents/detail/KDCW_MF00000030010000_68/