One of the upcoming Summer 2021 anime to keep an eye on is How a Realist Hero Rebuilt the Kingdom, based on the light novel series by Dojyomaru. The latest update is here with some more info on new cast members, as well as the official reveal of a July 3 premiere date in Japan.
New cast members getting in on the adaptation include Mugihito (Rom in Re:ZERO) as Albert Elfrieden, Kikuko Inoue (Cecile Croomy in Code Geass) as Elisha Elfrieden, Tetsu Inada (Endeavor in My Hero Academia) as Gaius Amidonia, and Kenji Nojima (Saiki in The Disastrous Life of Saiki K.) as Julius Amidonia. You can see them along with the date confirmation in the latest promotional video below.
J-Novel Club publishes the original novels digitally in English and sums up the story:
"O, Hero!" With that cliched line, Kazuya Souma found himself summoned to another world and his adventure--did not begin. After he presents his plan to strengthen the country economically and militarily, the king cedes the throne to him and Souma finds himself saddled with ruling the nation! What's more, he's betrothed to the king's daughter now...?! In order to get the country back on its feet, Souma calls the wise, the talented, and the gifted to his side. Five people gather before the newly crowned Souma. Just what are the many talents and abilities they possess...?! What path will his outlook as a realist take Souma and the people of his country down? A revolutionary transferred-to-another-world administrative fantasy series starts here!