Takarakuji de 40 Oku Atattandakedo Isekai [ongoing]

Kazura was selected as the winner on a lottery that he bought on a whim, and received 4 billion yen
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

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

The culture and technology level of that world was relatively low
The protagonist sometimes brought goods, sometimes brought technological knowledge
At that world, he would find his true value as a person