Long-long time ago, in an another dimension and space that unknown to all of us, there was only empty blank white space. As time passes by Billions of light years, a black dot start to formed in the middle of the blank. The Dot shape is Icosahedron, it have 20 sides and slowly...it became the first ever sentient being in the blank Universe. The Dot then started to rotate in the middle of the blank space , another smaller dot appeared each time it spin, it created another small dot resembles stars/planets and galaxy across the empty blank, another million years passes, and one of the 20 side from the Dot start glowing, The creation ability of the dot grow stronger, and once it reached 20 million years, All surfaces of the dot glowing in different colors, The dot now have omnipotent ability it then decided to find someone from another universe to Complete the final world building project ,it was "to created lives" and it choses Tamaru as holder of the D20 (DOT 20) and make the isekai that he dreamt of come true good and bad...but at the cost of him only can be the watcher/observer, now its up to the players from another worlds to created their own adventures and stories whichever they want. Welcome to TAMARU NO FANTASY.